Rainbow Mosaic Cake

Rainbow Mosaic Cake – how to make a pastel rainbow M&M cake with an eye-catching geometric pattern. A new tutorial by our contributor Whitney DePaoli.

In my humble opinion, Easter is the BEST time of year for candy. Not only is it tastier than ever (hello, Cadbury Mini Eggs!), but the pastel colors have me all starry-eyed and inspired! As I was recently browsing the Easter candy aisle, I couldn’t help but get all hung up on the seasonal color palette that M&Ms have got going on. After bringing them home and drawing up some ideas, I figured they’d make the perfect pastel mosaic as a cake finish and here’s what happened:

So pretty, right? I will admit, the geometric design does take some planning (I’ll help you with that below!) but the results are so eye-catching. And once you get into the groove of placing the candies, the process is super therapeutic! It’s basically like putting together an edible puzzle, and since there’s no complicated technique involved, it’s the perfect project for any skill level. Just put on a great album, sneak a few candies every now and then, and put those pieces into place!

This Rainbow Mosaic Cake can be made any time of year with all sorts of color palettes and candy shapes, so don’t feel limited to pastel if vibrant colors are more your style. Whatever color palette you go with, this cake is sure to be a true showstopper. And best of all, it couldn’t be easier to whip up – a total win win in my book!

RAINBOW MOSAIC CAKE
a tutorial by Whitney DePaoli

Supplies:

A 6-inch layer cake that’s been filled and crumb coated
Icing scraper
Angled spatula
Cake turntable
Straight ruler
2 Cups of buttercream
2 pounds of Easter M&M’s

PLAN OUT YOUR DESIGN

Before you get all excited to frost the cake and start placing your candies, it’s best to do a little planning session. Start by placing your candies out on a flat surface so you can get a rhythm going. Here’s what my design looks like out on the table. If you want to recreate this same geometric pattern, just copy my design as a guide. Another option would be solid rows, in traditional rainbow form.

BEGIN FROSTING THE CAKE

With your crumb coated cake on the turntable, frost the top of the cake with a thin, level layer of buttercream. Next, frost the sides of the cake and smooth them with your icing scraper, ensuring that they’re as smooth and straight as can be. Don’t smooth out the top edges just yet.

TAKE MEASUREMENTS

Before you smooth the top edges of the cake, measure the sides of the cake with a straight ruler or bench scraper that shows measurements. You’ll use this measurement to see how many rows of M&M’s you’ll need to reach the top, and also see if you need to add more buttercream to the top of the cake to compensate for the top row.

Using your measurement of the height of the cake, measure the amount of M&M rows you’ll need to reach the top using the flat pattern you created in Step 1. If you need more buttercream added to the top, now is the time to add that additional buttercream.

SMOOTH THE TOP EDGES OF THE CAKE

After your height is the at the perfect height, smooth the top edges of the cake using an angled spatula. Swipe the top edges inward to create sharp edges all around your cake.

PLACE THE M&M’s ONTO THE CAKE

Now that the icing is smooth, level, and still a bit wet to the touch, start placing the M&Ms using the design you planned out as a guide. Start at the bottom of the cake and work your way up to the top edge.

Once you’ve reached the top edge, all that’s left to do is fill in the top. I’ve found that the easiest pattern is to create circular rows of each color, but feel free to get creative with your design!

And just like that, you have an easy yet eye-catching Rainbow Mosaic Cake! It’s tasty, colorful, and is sure to turn all the heads. If you’re planning making the cake ahead and serving it the next day, feel free to pop it in the refrigerator until you’re ready for it. The coldness will help the candies set firmly, so you can be sure your masterpiece is preserved.