Amazing Costco Muffin Hack! | How to Decorate a Cake

Try this amazing Costco muffin hack and learn all the basic techniques for frosting and decorating a delicious, mini cake!

**Jump to the recipe card for simplified instructions!**

This Costco muffin hack is the perfect way to jump into cake decorating because it uses a smaller amount of ingredients per cake, you can try different techniques on different muffins, you can skip the baking part to save time, the muffins are cheap and huge, and they make delicious gifts!

And they’re so stinkin’ cute!!

Watch the whole process here:

Thanks Rebecca!

My sister, Rebecca, used to make and sell awesome cakes many years ago.

She made my wedding cake and our sister Victoria’s too.

**You can see more of her cake pictures in my video 👀👆🏻**

She’s really talented in all kinds of things, including singing, by the way. You can check out her Youtube channel here: Rebecca Tanner Music

Supplies For This Costco Muffin Hack

-Costco muffins. They come in different flavors depending on the season. Currently you can get 12 muffins for about $10. I tried to just buy 1 package with 6 muffins yesterday but they wouldn’t let me so it’s all or none. These are huge muffins. It’s like 4 muffins in 1. So you’re buying 48 muffins essentially. And I didn’t have to do any of the baking or wash any dishes. Dreams come true.

-Buttercream to frost. I used Wilton’s Vanilla Buttercream Recipe and it worked really well. I’ll talk a little more about it in the next section. Homemade is gonna taste better but you can also just go buy a tub of medium consistency cake frosting in the cake isle at Walmart or HERE on Amazon. Just make sure it says medium not stiff consistency.

–Spinning cake plate, lazy susan, or some paper plates. You just need something you can set the muffin on and turn it easily. We used paper plates in the video. Just use what you got!

-Piping tips. We used Wilton numbers 3, 10, 12, 21, and 32. You can find those HERE and HERE. You can grab whatever tip you want and then just practice different swirls and lines on a plate to see what you can do. Then you just scrape it up and put it back into the bag.

–Some Couplers and Rings. You need these if you want to switch the tips between different frosting bags, if you have different colors.

–Piping Bags. I used to just use freezer storage bags but they changed the design on the corners and it makes it really hard to use for piping now. Getting actual piping bags is cheaper than I thought and they work so well.

–Offset spatula or butter knife. You just need something with a flat, smooth edge to apply the frosting. Turn the knife over and use the back edge if you don’t have an offset spatula.

– Serrated knife. This is for leveling and cutting the layers. A dull, regular knife could squish the cake as you try to cut into it. A serrated knife just saws through – even if it’s dull.

–Sprinkles and candy to decorate. I just grabbed things from the holiday baking section.

-Paper towels.

-Plastic wrap. You need to keep the frosting covered as you work to keep it from crusting over.

-Bowls and spoons. For mixing different frosting colors.

-Scissors.

–Food dye.

-Cake fillings. You can just do frosting between the layers but it’s fun to experiment with different flavors here too! We used fudge ice cream topping inside a pumpkin muffin and it was the best!

Let’s Talk About Frosting

We made 4 batches of the Wilton vanilla buttercream for 6 muffins but we probably only needed two batches.

BUT it’s always better to have too much than too little though. And you can freeze it if you have extra or make cake balls with the extra frosting and muffin pieces! (Recipe in a section at the end)

Whip the frosting until it’s light and fluffy.

The frosting should be smooth and pretty easy to spread without a lot of resistance but it can still hold its shape.

If it’s too thick, it’ll rip the cake when you try to spread it.

Scoop some into individual bowls and mix in whatever colors you want. **Make sure to leave some plain white if you need it for your design.

Make sure to keep the frosting covered with plastic wrap as you work with it so it doesn’t dry and form a crust.

You can also add other things to the frosting to change the flavor – like crushed up Oreos, cocoa powder, candies, etc. Just make sure the texture is the same as before. When we added Oreos, we crushed them up very finely and then had to add a little bit of water to get it spreadable again.

How to Thaw Frosting From the Day Before Without Melting It

We had to make all the frosting the day before and stick it in the fridge so it was too cold and hard to work with.

To thaw frosting without melting it put it in the microwave and press cook time, then 30 seconds, then press power level, the select 2 and then start.

Take it out and stir it really well.

Then do the same thing as before but for 20 seconds on power lever 2.

Mix thoroughly and it should be the right consistency now.

How to Cut Cake Layers Without a Cake Leveler

Pull the paper off of a muffin and place it on something you can easily turn on your work surface. Like a turntable or an upside down plate.

With a cake this tiny, you can either glue it down with a little but of frosting on the bottom or leave it free. Do what works the best for you.

Using a long serrated knife, lightly score the cake just under the muffin top all the way around and keep turning the cake as you cut deeper and deeper, a little at a time, until you get all the way through.

This method helps you to make a level cut across the top and keeps the cake intact.

If you just cut it straight across, you often end up ripping a chunk out of the opposite side. You could probably do it with this tiny of a cake, but the larger the cake, the more this method helps.

Put the top aside as leftover. (see the section below about making cake balls)

Use the same method to cut the cake into two layers.

Now use something to flick all the crumbs off of the plate before you start frosting.

How to Insert Piping Tips and Couplers

To use just the piping tips, insert a tip into an empty bag and push it down as far as it’ll go.

Use some scissors to score the bag towards the end of the piping tip then scoot the tip back up and out of the way so you can cut the bag where you marked it.

Push the tip back down until it’s snug and it’s ready to fill.

If you want to be able to switch the piping tips between the bags of frosting, you want to use couplers with rings.

Take the ring off of the coupler and push it down into the empty piping bag. Score it towards the end with a pair of scissors, just like with the piping tip.

Push it back up and out of the way so you can cut the end of the bag off then push it back down until it’s snug.

Fit a piping tip over the outside of the bag and over the coupler and then screw a ring over that.

Now to switch a tip you just unscrew the ring, change the tip, and screw the ring back on.

If any of this is confusing, just watch the video and see how we do it.

How to Fill a Piping Bag

To fill the piping bag, fold the edges down then spoon the frosting in.

Roll the edges back up, squish the frosting down to the tip then twist the bag at the top of the frosting.

Costco Muffin Hack – Let’s Fill Our Cake!

You can just fill your cake with frosting and that is perfectly fine.

Or you can use whatever you like to fill your cakes: fruit, jam, candy, pudding, custard, chocolate chips, nuts,

To make sure the filling stays between the layers and doesn’t seep out, you can pipe a ring of frosting around it. This will be a little wall for the filling and also gives the top layer of cake something more stable to sit on. We used a number 12 round tip for this.

To pipe, squeeze the frosting out with even pressure, making sure to hold the twist in the bag so the frosting can’t come back up and out the top.

Keep twisting the bag tighter as you pipe to keep the tension on the frosting.

While one hand pipes the frosting, use your other hand to support and keep it steady. Figure out what’s comfortable for you.

If your frosting wall is a little flat in places, just add a little more! No problem!

We used ice cream fudge topping to fill a pumpkin cake. It’s pretty much just premade ganache. It was delicious!

Place the top layer on and you’re ready to frost the whole thing!

This Costco muffin hack is so fun!

What’s a Crumb Coat?

A crumb coat is when you cover the cake in a thin layer of the frosting.

It’s just enough to glue done all the crumbs to the cake and fill all the little crevices. Just follow the shape of the cake and don’t worry about the crumbs mixing in with the frosting or being too careful.

Just don’t be so rough that you rip the cake.

If you’re not real sure about your frosting skills, you have a very delicate cake, and you have some extra time, a crumb coat is a good option.

If you’re using the chocolate muffins or anything with chunks in it, it’ll be easier if you do a crumb coat and chill that kind too.

Hold the spatula perpendicular to the cake as you frost the sides. It’s more comfortable like that.

Remember you can either use an offset spatula if you have it, or the flat side of a butter knife.

Completely cover the cake and take off any excess frosting. You’ll totally be able to see the cake through the frosting.

Throw that in the fridge or freezer to get really cold and firm. That’s an important step if you’re doing a crumb coat.

How To Frost a Cake Without a Crumb Coat

If you’re frosting without a crumb coat, you have to be careful to not get crumbs in the frosting.

If you spread the frosting on and you spread until you run out of frosting, when you lift up you’ll have crumbs on the spatula.

The trick is to get enough on the spatula and then use a back and forth motion, always keeping within the frosting glob.

I know this sounds confusing. Just watch the video and it’ll totally make sense.

How to Frost Your Costco Muffin Hack Cake

Get a lot of frosting on the cake and swipe your spatula or butter knife back and forth, back and forth as you push it equally over the edge, turning the whole time.

This is why it’s good to have a lot of extra frosting. It won’t all end up on the cake but it’ll make it easier to frost.

The more frosting you put on, the easier it is to keep the crumbs contained and it’s easier to shape the cake how you want.

Grab some more frosting and smoosh it onto the side of the cake using the same motions, back and forth back and forth, staying inside the frosting.

Once you’ve got the side covered, you want to continue to smoosh the icing around as you pull up a little because you want to have kind of a crown on the top edge of the frosting.

You want the entire top edge to come up higher than you want it to be at the end.

When you’ve got a nice crown of frosting, keep your spatula straight down and start smoothing the sides as you take off the extra frosting.

Don’t take any off the top yet.

It works the best if you make a pass, wipe the spatula on the edge of the frosting bowl to deposit excess frosting, and then wipe your spatula with a paper towel so you’ve got a clean edge to smooth with every time.

When the sides are as smooth as you want them, hold your spatula horizontally and make a swipe across the top edge from the outside in, toward the middle of the cake.

Turn the cake as go until you have a nice flat top.

While the cake is still wet, now is the time to decorate with sprinkles if you want them.

Put the cake back into the fridge to firm up if you need to transfer it to another plate or finishing platter.

If you want an ultra smooth cake, you can heat you spatula in hot water, dry it and then run the knife across the frosting. This will melt it a tiny bit and make it smoother.

Then you can let it crust a little and use a little bit of smooth parchment paper and rub it against the frosting to smooth out any lines too.

How to Decorate Your Costco Mini Muffin Cake

The sky’s the limit here.

****Remember you can always scrape it off and try again!

Or move on to the next mini cake and practice it again. Don’t get too hung up on making things perfect. Take a step back every so often and appreciate what you’ve been doing.

Sprinkles can cover a multitude of mistakes and it won’t matter it you couldn’t get the frosting super smooth.

Using an open star tip (we used a number 21) and a swirling motion, you can create rosettes or swirls on top of your cakes.

These make a big impact and are adorable in white, colors, by themselves or with things placed on top of them.

Just pipe in a circle as you pull up. The bigger the circle, the bigger the swirl.

You can always practice on a plate or paper towel first and then scoop that back into the bag.

The best thing about these is that you can use a spatula to move them over a little if you spaced them out wrong. Especially if you piped them on top of sprinkles!

And if the swirl is a little off, just stick a mini Oreo or red candy (looks like a cherry) and that makes the swirls perfect again!

You can cover the bottom edge with a sprinkles, rosettes, candy, or a simple beaded frosting border.

To make the beaded border: using a number 10 circle tip, squeeze while holding in one spot and then pull to the side. Repeat that as you go around the cake.

It’s always better to start at the back of the cake in case it comes out weird or doesn’t quite match when you get back to the starting point.

Use a number 3 round tip if you want to do any writing or thin lines on your cake. If you get an air bubble and it breaks the line of writing, just add some frosting there and (while the frosting is still wet) use a toothpick to wiggle it into place and smooth the transition.

***You don’t have to pipe stuff to decorate your cake.

You can just use pre-made sugar decorations to finish it off. Look at these examples HERE, HERE, and HERE. There are so many out there.

Look in the baking and cake isles of the store. Add a glob of frosting on the back to attach them to the cake and call it good!

You can also pick a toy to use a cake topper and then coordinate the cake color with that. Add some swirls or candy and sprinkles and it’s done! It looks amazing and the kid gets a toy to play with after the cake is gone!

I just love decorating these Costco muffin hack mini cakes! They’re adorable!

Here are more cakes we made and our kids made!

How to Add a Drip Border to the Top of a Cake

Heat a small amount of frosting until it’s runny. You can also use actual melted chocolate.

We used some premade chocolate frosting from a can but it works with the regular frosting too.

The fudge ice cream topping did NOT work for this application. It just wouldn’t get runny for some reason.

Spoon or pipe the warm frosting over the edge to get a nice cascade of drips all around and then fill in the middle.

You need to work quickly if you’re using a chilled cake.

Make Some Cake Balls After Your Costco Muffin Hack

This is a great way to use up extra ingredients after doing this Costco Muffin Hack!

To make cake pops out of the left over frosting and muffin tops, crumble up the muffin into fines crumbs.

You need about 1 and 1/2 times the amount of cake as frosting. So, for 1 and 1/2 cups of cake crumbs you need 1 cup of frosting.

Mix those together really well until you have a scoop-able dough. Use a cookie scoop to make little balls and roll them in your hands to make them smooth then place them on a cookie sheet lined with parchment paper.

Dip one end of a lollipop stick into some melted chocolate and stick that into each ball. Stick the finished pan into the freezer for about and hour then quickly dip each ball into more melted chocolate.

You can stick them into a chunk of Styrofoam to harden all the way or put them back down on the pan for a flat top.

Sprinkle with decorations while still wet or pipe on frosting decorations once they’re set. Have fun!

Don’t forget to pin it!

Don’t forget to print the tutorial for later!