I posted pictures of a big M&Ms-stuffed chocolate cake on my social media last week and y’all went crazy for it!I get it—chocolate cake + buttercream + M&Ms inside + more M&Ms on top = MAGIC.That original cake was for a friend and not intended for the blog, but given the response, I thought you might like to know how to make your own!First things first. You’re going to need four 9-inch round layers of chocolate cake. This one is a super easy no-mixer recipe that makes four soft, moist, perfect layers. You may recognize this recipe from my my Chocolate Cake with Malted Chocolate Buttercream—it’s exactly the same except that I scaled it up by 50%.Place one of the layers on a serving plate or your favorite of all your cakestands. Spread a little frosting on top.Take two of the layers and punch out holes in the centers. I use a 6-inch ring for this, but you can use a wide-mouthed glass or even just a paring knife and a circle of parchment. Layer those on top of that bottom round, frosting between and on top.At this point, you’ll have a three layer cake with a hole in it. That’s where the surprise M&Ms are going to go ❤Spread a thin layer of buttercream on the “walls.” This will help keep the moist cake from melting the color off the M&Ms too quickly. And speaking of M&Ms……pour in almost 2 cups of them ❤ ❤ ❤Place your last intact layer of cake on top, effectively hiding all that surprise candy. Frost the cake. For a sort-of photo tutorial on that, see last week’s Cinnamon Buttercream post.I decorated the top with even more M&Ms and used the last of the frosting to pipe a border. The dollops are all different sizes and I love it!

Gather all your family, friends, neighbors, coworkers—really, anyone will do. Get them all around the table so they can see this amazing thing you’ve made in all it’s rainbow candy avalanche glory. This cake is delicious—with that much chocolate and butter, it has to be—but the magic is in the presentation.Then again, I was alone when I sliced this sucker open and it was still pretty damn magical. But I also took 200+ photos of it for you, so I suppose you were practically there.

M&Ms Surprise Cake
makes 1 large 9-inch round cake

Cake:
2 2/3 cups all purpose flour
1 cup + 2 Tbsp natural unsweetened cocoa powder
1 2/3 cups granulated sugar
1 cup light or dark brown sugar, packed
1 1/2 teaspoons baking powder
1 tablespoon (3 teaspoons) baking soda
1 1/2 teaspoons Kosher or sea salt
3/4 cup neutral-flavored oil (I like canola)
3 large eggs, room temperature
1 tablespoon pure vanilla extract
1 1/2 cups buttermilk
1 1/2 cups strong, hot coffee

Chocolate Buttercream:
2 cups (4 sticks) unsalted butter, softened to room temperature
5 1/2 cups confectioners sugar
1 1/4 cups natural unsweetened cocoa powder
pinch of Kosher or sea salt
2 teaspoons pure vanilla extract
1/2-2/3 cup heavy cream

For Assembly:
1 3/4 cups M&Ms candy, plus more for decoration

Preheat the oven to 350F. Grease 4 9-inch round cake pans. Line the bottoms with parchment and grease again. Set aside.

Make the cake batter. In a large mixing bowl to sift together flour, cocoa powder, granulated sugar, dark brown sugar, baking powder, baking soda, and salt. Set aside.

In a separate large mixing bowl, whisk together oil and eggs, followed by vanilla, buttermilk, and coffee. Whisk in dry ingredients in three installments, just until combined. Divide batter evenly among the pans. Tap full pans on the counter five times to release any air bubbles. Bake 20-22 minutes, or until a toothpick inserted in the middle comes out clean.

Let cakes cool in pans for ten minutes before running a small, thin knife around the edges. Invert cakes onto cooling racks and allow to cool to room temperature.

Make the chocolate buttercream. In a large mixing bowl, use an electric mixer to beat butter until light and fluffy (about two minutes). Beat in confectioner’s sugar, followed by cocoa powder and salt, scraping down the bowl as necessary. Add in vanilla and 1/2 cup heavy cream. Beat on high for 1-2 minutes, until very fluffy. Add up to 2 more tablespoons of heavy cream, until desired consistency is reached.

Assemble cake. Place one round on a serving plate and top with a layer of frosting. Set aside.

Use a 4-6 inch cutter (or a wide-mouthed cup or jar) to cut the centers out of two layers. Set centers aside for another use. Place one cut-out layer on the bottom layer and top with a layer of frosting. Place the other cut-out layer on top and frost. Coat the inside of the hole with a thin layer of frosting.

Fill the hole in the cake layers with M&Ms. Top with the last (fully-intact) layer of cake. Frost cake as desired. Decorate with more M&Ms, as desired.

Layer cake will keep covered at room temperature for up to three days, or in the refrigerator for up to a week. M&Ms may lose their color over long periods of time.