Peanut Butter Sheet Cake with Peanut Butter Frosting

Here’s a  recipe for Peanut Butter Sheet Cake with Peanut Butter Frosting — a rich, moist cake layered with creamy peanut butter frosting. Perfect for gatherings or whenever you want something sweet and peanut-buttery!

Peanut Butter Sheet Cake

Ingredients:

For the Cake:

• 2 cups all-purpose flour

• 2 cups granulated sugar

• 1/2 teaspoon salt

• 1 teaspoon baking soda

• 1 cup (2 sticks) unsalted butter

• 1 cup water

• 1/2 cup buttermilk (or 1/2 cup milk + 1/2 tablespoon vinegar, let sit 5 minutes)

• 3 large eggs

• 1 teaspoon vanilla extract

• 1 cup creamy peanut butter (natural or regular)

For the Peanut Butter Frosting:

• 1 cup (2 sticks) unsalted butter, softened

• 1 cup creamy peanut butter

• 3-4 cups powdered sugar (confectioners’ sugar), sifted

• 1/4 cup milk (more as needed)

• 1 teaspoon vanilla extract

Instructions:

Cake:

1. Preheat Oven & Prepare Pan
   Preheat your oven to 350°F (175°C). Grease and flour a 9×13 inch sheet pan or line it with parchment paper.

2. Mix Dry Ingredients
   In a large bowl, whisk together the flour, sugar, salt, and baking soda. Set aside.

3. Heat Butter and Water
   In a medium saucepan, combine the butter and water. Bring to a boil over medium heat, stirring occasionally until butter melts and the mixture comes to a boil.

4. Combine Wet & Dry
   Pour the hot butter and water mixture over the dry ingredients. Stir until combined — it will be thick.

5. Add Peanut Butter
   Stir in the peanut butter while the batter is still warm so it blends smoothly.

6. Mix Buttermilk, Eggs, and Vanilla
   In a separate bowl, whisk together the buttermilk, eggs, and vanilla extract.

7. Combine All
   Gradually stir the buttermilk mixture into the batter. Mix until smooth and fully incorporated.

8. Bake
   Pour the batter into the prepared pan and smooth the top with a spatula. Bake for about 30-35 minutes, or until a toothpick inserted in the center comes out clean.

9. Cool
   Let the cake cool completely in the pan on a wire rack before frosting.

Peanut Butter Frosting:

1. Cream Butter & Peanut Butter
   In a large bowl, beat the softened butter and peanut butter together until smooth and creamy.

2. Add Powdered Sugar
   Gradually add powdered sugar, about a cup at a time, mixing on low speed until combined.

3. Add Milk & Vanilla
   Add the vanilla extract and milk, then beat on medium speed for 2-3 minutes until fluffy. Add more milk if frosting is too thick, or more powdered sugar if too thin.

4. Frost Cake
   Spread the frosting evenly over the cooled cake.

Optional Toppings:

• Chopped peanuts for crunch

• Mini chocolate chips

• A drizzle of melted chocolate

Tips:

• Use creamy peanut butter for the smoothest batter and frosting.

• Make sure cake is fully cooled before frosting to avoid melting the frosting.

• You can refrigerate the cake after frosting for a firmer texture; bring to room temp before serving.