Chocolate Birthday Peanut Cake Recipe
Make Chocolate Birthday Peanut Cake Recipe in just 2h 30m. Get the full recipe with step-by-step instructions at pekinthechef.com.
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Ingredients
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Peanut Cake Layers
Chocolate Peanut Butter Frosting
Peanut Crunch & Decoration
Cake Assembly / Tools
Method
Peanut Cake Layers
- 1
Prep
Preheat oven to 350°F (175°C). Position oven rack to center. Grease two 8-inch round cake pans with nonstick spray or butter and lightly dust with 1 tablespoon flour; tap out excess.
- 2
Dry ingredients
In a large bowl, sift or whisk together 2.25 cups all-purpose flour, 1.5 cups granulated sugar, 0.75 cup unsweetened cocoa powder, 2 tsp baking powder, 1 tsp baking soda, and 0.5 tsp kosher salt until uniform.
- 3
Wet peanut mixture
In a medium bowl, whisk 0.75 cup creamy peanut butter with 0.5 cup vegetable oil until smooth and slightly loose. Add 3 large eggs one at a time, whisking after each until incorporated. Stir in 1 cup buttermilk and 2 tsp vanilla extract until combined.
- 4
Combine dry and wet
Make a well in the dry ingredients and pour in the peanut-wet mixture. Stir gently with a spatula just until combined and no large streaks remain.
- 5
Add hot water
Gradually add 1 cup hot water to the batter while stirring slowly; the batter will be thin — this helps keep the layers moist and helps dissolve cocoa. Scrape down the bowl and give one final gentle stir.
- 6
Bake
Divide batter evenly between the two prepared pans. Bake on center rack for 28–34 minutes, or until a toothpick inserted in the center comes out with a few moist crumbs (not wet batter). Rotate pans halfway through baking for even browning.
- 7
Cool
Allow cakes to cool in pans on a wire rack for 10 minutes. Run a thin knife around edges, invert onto racks, remove parchment (if used), then invert again so cakes are right-side-up. Cool completely (at least 1 hour) before frosting.
Chocolate Peanut Butter Frosting
- 8
Soften butter & mix
Beat 1 cup room-temperature unsalted butter in a large bowl with a hand or stand mixer on medium speed until creamy, about 1–2 minutes.
- 9
Add peanut butter & cocoa
Add 0.75 cup creamy peanut butter and 0.5 cup unsweetened cocoa powder to the butter. Beat on low to combine, then increase to medium until smooth, about 1 minute.
- 10
Add powdered sugar & cream
With mixer on low, add 4 cups powdered sugar in two additions to avoid a sugar cloud. Add 3 tbsp heavy cream, 1 tsp vanilla extract, and 0.25 tsp salt. Increase speed to medium-high and beat for 1–2 minutes until light and fluffy. If frosting is too stiff, add 1 tsp more cream at a time until spreadable; if too loose, add 2–4 tbsp more powdered sugar.
Peanut Crunch & Decoration
- 11
Prepare chopped peanuts and brittle
Roughly chop 1 cup dry-roasted peanuts and, if using, 0.5 cup peanut brittle or clusters. Reserve about 0.5 cup peanuts/brittle for decorating the top and sides; the remainder will be used in and between layers for crunch.
- 12
Make chocolate glaze
Melt 4 oz semisweet chocolate with 1 tsp vegetable oil in a microwave-safe bowl in 20–30 second bursts, stirring between, until smooth. Let cool 3–5 minutes until slightly thickened but still pourable.
Assembly
- 13
Level layers
If cake domes are present, level the tops with a serrated knife to create two flat layers. Retain crumbs for later if doing crumb coat.
- 14
First layer
Place one cake layer on your serving plate or cake board. Spread a thin layer (about 3/4 cup) of the chocolate peanut butter frosting over the top, then sprinkle 1/3–1/2 cup of the chopped peanuts and brittle evenly over the frosting to create a crunchy layer. Lightly press so pieces adhere.
- 15
Top layer & crumb coat
Place the second cake layer on top and apply a thin crumb coat of frosting (about 1/2 cup) around the sides and over the top to lock in crumbs. Refrigerate for 20 minutes to set the crumb coat.
- 16
Final frost
Apply the remaining frosting in an even thicker layer over the top and sides. Use an offset spatula to smooth sides and create a slight swirl on top if desired.
- 17
Add chocolate glaze
Spoon the cooled but still-pourable chocolate glaze over the center of the cake and gently nudge it to create a small drip toward the edges. Use the back of the spoon to spread a thin glossy circle or allow natural drips to form.
- 18
Decorate
While glaze is tacky, press the reserved chopped peanuts and brittle around the base and scatter some on top. Add sprinkles or other birthday decorations as desired. If you want extra peanut butter ribbons, pipe small rosettes of frosting around the top edge before adding decorations.
- 19
Chill & serve
Refrigerate the assembled cake for at least 30 minutes to set the frosting and glaze. Remove from fridge 20–30 minutes before serving for easiest slicing. Slice with a sharp knife wiped between cuts for clean pieces.