Peanut Butter Cake with Peanut Butter Frosting
Ingredients
For the Cake (9×13-inch pan or 2 round layers)
- 1 ¾ cups all-purpose flour
- 1 tbsp baking powder
- ½ tsp baking soda
- ½ tsp salt
- ½ cup unsalted butter, softened
- 1 cup creamy peanut butter
- 1 ¼ cups brown sugar
- 3 large eggs
- 1 tsp vanilla extract
- 1 cup buttermilk (or 1 cup milk + 1 tbsp vinegar/lemon juice)
For the Peanut Butter Frosting
- ½ cup unsalted butter, softened
- 1 cup creamy peanut butter
- 2 cups powdered sugar, sifted
- 3–4 tbsp heavy cream or milk
- 1 tsp vanilla extract
- Pinch of salt
Instructions
1. Make the Cake
- Preheat oven to 350°F (175°C). Grease and flour your baking pan(s).
- In a bowl, whisk together flour, baking powder, baking soda, and salt.
- In a large mixing bowl, beat butter and peanut butter until creamy. Add brown sugar and beat until fluffy.
- Add eggs one at a time, then mix in vanilla.
- Alternate adding dry ingredients and buttermilk, mixing just until combined.
- Pour batter into the prepared pan(s).
- Bake 30–35 minutes (9×13 pan) or 25–30 minutes (round layers), until a toothpick comes out clean.
- Cool completely before frosting.
2. Make the Frosting
- Beat butter and peanut butter until smooth.
- Gradually add powdered sugar, mixing well.
- Add vanilla, salt, and just enough cream/milk to reach a fluffy, spreadable consistency.
3. Frost & Serve
- Spread frosting evenly over the cooled cake.
- Garnish with chopped peanuts, peanut butter cups, or a drizzle of melted chocolate if desired.
Why You’ll Love It
Super moist with deep peanut butter flavor
Fluffy, creamy frosting that’s not overly sweet
Great for birthdays, potlucks, or any peanut butter fan
Easy to adapt into cupcakes
Pro Tip: For a bakery-style finish, chill the cake after frosting for 20 minutes, then drizzle with warm chocolate ganache for a peanut butter–cup vibe.
