Here’s a rich, ultra-moist Peanut Butter Sheet Cake with Peanut Butter Frosting—perfect for feeding a crowd and super easy to make:
🥜 Peanut Butter Sheet Cake
🧾 Ingredients
For the cake:
- 2 cups all-purpose flour
- 2 cups granulated sugar
- 1 tsp baking soda
- ½ tsp salt
- 1 cup unsalted butter
- 1 cup water
- ½ cup creamy peanut butter
- ½ cup vegetable oil
- 2 large eggs
- ½ cup buttermilk
- 1 tsp vanilla extract
For the peanut butter frosting:
- ½ cup unsalted butter
- ½ cup creamy peanut butter
- ¼ cup milk
- 1 tsp vanilla extract
- 3–4 cups powdered sugar (adjust for thickness)
- Pinch of salt
👩🍳 Instructions
1. Prep
- Preheat oven to 350°F (175°C)
- Grease a 9×13-inch sheet pan
2. Mix dry ingredients
- In a large bowl, whisk together flour, sugar, baking soda, and salt
3. Make peanut butter mixture
- In a saucepan, combine butter, water, peanut butter, and oil
- Heat until melted and smooth (don’t boil)
4. Combine
- Pour hot mixture into dry ingredients and mix well
- Add eggs, buttermilk, and vanilla
- Beat until smooth
5. Bake
- Pour batter into pan
- Bake for 30–35 minutes or until a toothpick comes out clean
🍰 Peanut Butter Frosting
6. Make frosting
- In a saucepan, melt butter and peanut butter together
- Stir in milk and vanilla
- Remove from heat and whisk in powdered sugar until smooth
- Add a pinch of salt
7. Frost the cake
- Pour warm frosting over the warm cake
- Spread evenly—it will set into a soft, fudgy layer
✨ Tips
- Sprinkle chopped roasted peanuts on top for crunch
- Add a drizzle of melted chocolate for a peanut butter–chocolate combo
- Best served slightly warm or at room temperature
If you want, I can give you a chocolate peanut butter version, a healthier version, or convert this into cupcakes 👍