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peanut butter chocolate cake
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Chocolate Peanut Butter Cake

Layers of moist, fluffy Peanut Butter Cake topped with Chocolate Peanut Butter Buttercream. The dreamiest of all decadent flavor combo. 

Ingredients

Peanut Butter Layer Cake

  • 3 1/2 Cups (370g) cake flour, sifted before measuring
  • 1 Tbsp baking powder
  • 3/4 tsp baking soda
  • 1 1/2 tsp kosher salt
  • 1 1/8 Cup (254g) unsalted butter, room temperature
  • 1 Cup (205g) granulated white sugar
  • 1/2 Cup (94g) packed brown sugar
  • 1 Cup (250g) creamy peanut butter
  • 4 eggs, room temperature
  • 1/3 Cup (75g) sour cream, room temperature
  • 1 1/2 Tbsp vanilla extract
  • 1 1/2 Cups (360ml) whole milk, room temperature

Chocolate Peanut Butter Buttercream

  • 1 1/2 Cups (339g) unsalted butter, room temperature
  • 1/3 Cup (83g) creamy peanut butter
  • 4 1/2 Cups (540g) powdered sugar
  • 3/4 Cup (63g) natural unsweetened cocoa powder
  • 6 Tbsp (89ml) whole milk, room temperature
  • 1 Tbsp vanilla extract
  • 1/2 tsp kosher salt

Instructions

Make The Peanut Butter Layer Cake

  • Preheat the oven to 350°F. Prepare three 8-inch or four 6-inch cake pans by spraying the sides with a cooking spray (Baker's Joy is my favorite) and a wax paper circle fitted to the bottom of the pan. Alternatively, you can grease and lightly flour the pans.
  • Sift the cake flour and then measure by spooning and leveling it in your measuring cup. Add the cake flour, baking powder, baking soda, and salt into a bowl and whisk to combine. Set aside. 
  • In the bowl of your stand mixer (a handheld mixer works fine too!), cream the butter for on high for two minutes until it's light and fluffy. Add in white sugar, brown sugar, and peanut butter and continue to mix on medium-high for another three minutes, scraping down the bowl and paddle as needed. Add the eggs one at a time, mixing thoroughly after each addition. Add vanilla and sour cream and mix for one minute on medium-high, scraping down the bowl and paddle once more.
  • With the mixer on low speed, add in the dry ingredients and mix until just combined. Add the whole milk and mix until just incorporated. Scrape down the sides and bottom of the bowl and give it a few stirs to make sure there are no lumps. Batter will be thick.
  • Pour batter evenly into prepared cake pans (no more than 2/3 of the way full), smooth the tops, and bake for 35-40 minutes. They're done when they spring back to the touch and a toothpick inserted into the middle comes out clean. Let the cakes cool in the pan for five minutes before turning them out onto a wire rack for an additional few hours of cooling. Make sure they're entirely room temperature before applying any frosting.

Make The Chocolate Peanut Butter Buttercream

  • In a stand mixer fitted with a paddle attachment, whip the butter and peanut butter on medium speed until very creamy and well combined, about three minutes. Scrape down the bowl and paddle and turn the mixer to low, then add powdered sugar, cocoa powder, milk, vanilla extract, and salt. Increase the speed to medium and beat for two full minutes.

Assembly

  • Fill and frost the Peanut Butter Cake layers with the Chocolate Peanut Butter Buttercream. If you want to recreate the look that's pictured, frost a smooth finish with the buttercream, then refrigerate the cake for 30 minutes. Prepare a piping bag with Wilton Tip 4B, fill it with more Chocolate Peanut Butter Buttercream, then pipe open stars in an ombre pattern on the sides of the cake. Use the same piping tip to create a buttercream border on top, then top the cake with mini peanut butter cups and gold sprinkles. 

Notes

Make Ahead Tips: this cake can be made ahead and stored at room temperature, covered tightly in plastic wrap, for up to two days. Alternatively, you can cover with plastic wrap and store in the freezer for up to two months before thawing to room temperature. 
The buttercream can be made ahead and stored in an airtight container at room temperature for up to 1 day. Alternatively, you can store it in an airtight container in the refrigerator for up to two weeks. When you’re ready to use it, bring it back to room temperature and rewhip with your stand mixer to bring back to frosting consistency.