Back in November, I made this Chocolate M&Ms Cookie Cake for a friend’s birthday. I thought it was cute, so I posted a picture of it on my social media with a #comingsoon…and then promptly forgot* about it because Christmas, Valentine’s Day, Easter, my birthday, and so on and so forth.

*For the record, I did post a single-serve version.But I remembered now. Seven months later than anticipated, but I remembered. I promise you, Chocolate M&Ms Cookie Cake is worth the wait.We’re talking about a rich, thick chocolate cookie studded with colorful candy and finished off with a flourish of chocolate buttercream. What’s not to love?!It’s easy too—it’s basically just a slightly smaller batch of my Double Chocolate Cookie dough with M&Ms instead of chocolate chips.Bake it up in a cake pan, let it cool, and pipe on a buttercream border. In my opinion, that last step is the thing that takes this recipe from “giant cookie” to “cookie cake.” Not that there’s a thing in the world wrong with a giant cookie, am I right?!Slice it up and share with people you love this weekend or for the Fourth of July (with holiday-appropriate M&Ms!) or pretty much any old time. Or, you know, follow my lead and completely forget about it for seven months and then wonder why you didn’t make it sooner.

(Don’t be like me.)

Chocolate M&Ms Cookie Cake
makes 1 9-inch round cake

3/4 cup (1 1/2 sticks) unsalted butter, cut into pieces
1 cup light or dark brown sugar, packed
1/3 cup natural unsweetened cocoa powder
2 large eggs, room temperature
1 teaspoon pure vanilla extract
1 2/3 cups all-purpose flour
1 teaspoon baking soda
1/4 teaspoon Kosher or sea salt
1 cup M&Ms candy

For decoration:
Chocolate Buttercream (recipe below)
M&Ms candy

Preheat oven to 350F. Grease a 9-inch round cake pan with butter. Line the bottom with parchment and grease again. Set aside.

Combine butter, brown sugar, and cocoa powder in a microwave-safe bowl. Microwave in 30 second increments, stirring in between, until butter is melted. Mixture will be a bit grainy.

Let mixture cool a few minutes before transferring to a large mixing bowl. Whisk in eggs one at a time, followed by vanilla. Whisk in flour, baking soda and salt. Use a silicone spatula or wooden spoon to fold in M&Ms candy.

Transfer dough to prepared pan and spread into one even layer. Bake 24-27 minutes, or until the top no longer appears shiny.

Let cookie cake cool completely in the pan on a rack. Run a small, thin knife around the edge of the pan before inverting the cake onto the rack. Revert onto a serving plate. Decorate with Chocolate Buttercream and M&Ms as desired.

Decorated cake will keep at room temperature for up to two days, or in the refrigerator for up to five.

Chocolate Buttercream
makes about 1 1/2 cups

1/2 cup (1 stick) unsalted butter, softened to room temperature
1 1/4 cup confectioner’s sugar
6 tablespoons natural unsweetened cocoa powder
pinch of Kosher or sea salt
1 teaspoon pure vanilla extract
3 tablespoons heavy cream

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 heavy cream. Beat on high for 1-2 minutes, until very fluffy.

Load into a piping bag fitted with a tip (I used a star tip here), or spread with an offset icing knife.