Step1: Preheat the Oven

Preheat your oven to 350°F (175°C). Grease and line three 8-inch round cake pans with parchment paper for easy removal.

Step2: Prepare the Dry Ingredients

In a medium bowl, whisk together the all-purpose flour, baking powder, baking soda, and salt. Set aside.

Step3: Cream the Butter and Sugars

In a large mixing bowl, cream the softened butter, granulated sugar, and brown sugar until the mixture turns light and fluffy.

Step4: Add Eggs and Peanut Butter

Beat in the eggs, one at a time, ensuring each egg is fully incorporated before adding the next. Add the peanut butter and vanilla extract, mixing until the batter is smooth and creamy.

Step5: Combine Wet and Dry Ingredients

Gradually add the dry ingredients to the wet mixture, alternating with the buttermilk. Start and end with the dry ingredients. Mix until just combined—don’t overmix!

Step6: Bake the Cake Layers

Divide the batter evenly between the prepared pans. Smooth the tops with a spatula and bake for 25-30 minutes, or until a toothpick inserted in the center comes out clean.

Step7: Cool the Cakes

Allow the cakes to cool in their pans for about 10 minutes before transferring them to a wire rack. Let them cool completely before frosting.

Step8: Make the Frosting

In a large bowl, beat the softened butter and peanut butter together until creamy. Gradually add powdered sugar, one cup at a time, beating well after each addition. Slowly add the heavy cream until you reach your desired consistency.

Step9: Assemble and Frost the Cake

Place one cake layer on a serving plate and spread a generous amount of frosting on top. Repeat with the remaining layers. Cover the entire cake with the remaining frosting and decorate as desired.