I used to make my daughter a different birthday cake every year, depending on her special requests or birthday party theme. But one year I served a chocolate sheet cake with peanut frosting that I developed for work, and it was such a hit that I’ve made it at every birthday party ever since. Even when she’s requested a different cake we’ll have two cakes — the one she wants but also this one to serve to the grown-ups at her party (and let’s face it, because I want to eat it too).
This decadent chocolate cake has a pillowy, not-too-sweet peanut butter frosting that has garnered me much attention at her school. Even years later, parents have come to me to talk about the cake. Chances are, if it’s your birthday and you request a cake, this is what I will walk in the door carrying.
Get the recipe: Chocolate Sheet Cake with Honey-Roasted Peanut Butter Frosting
What Makes This Cake So Good
The deep chocolate flavor in the cake comes from mixing boiling water and natural cocoa powder together first. The heat in the water “blooms” the cocoa, or brings out its intense flavors, which in turn gives the cake a super-chocolate-y flavor. I love it because you don’t have to chop up any chocolate or melt it down, and I always have cocoa powder in my pantry.
The frosting is the superstar though. A whole jar (yup, you read that right!) of smooth honey peanut butter gets beaten with butter and powdered sugar until fluffy and ultra-dreamy (make something delicious with that empty peanut butter jar). It spreads onto the cake beautifully and the leftover frosting on the beaters makes for the best baker’s treat ever. When you take a bite of the cake and frosting together, it’s just the perfect blend of dark, moist chocolate cake with a not-too-sweet peanut butter frosting. It’s proof that peanut butter and chocolate are the best of friends.
Why This Recipe Really Works
You’ll need a mixer for both the cake and the frosting, but a stand mixer or a hand mixer work just fine here. The cake batter will seem thin, but bakes up tall in a 9×13-inch baking pan. I’ve made this successfully in a glass or metal baking pan (glass takes a bit longer).
The frosting is easy because you just beat all the ingredients together at once. If you like your frosting on the sweeter side, you can always add more powdered sugar. Once the frosting is spread onto a still-warm cake, you’re left with a cake that stays moist for days. You can make this cake the day before a birthday party, cover it, and store at room temperature until you’re ready to serve. The 9×13-inch baking pan is easy to transport and also easy to serve out of.