Description
This Peanut Butter Sheet Cake is a moist and flavorful dessert featuring a rich peanut butter cake base with a smooth and luscious peanut butter frosting. Perfectly baked in a 9x13-inch pan, this sheet cake brings the nostalgic taste of peanut butter in every bite, enhanced with subtle cinnamon and a creamy frosting that sets beautifully when poured warm.
Ingredients
Cake
- 1 1/4 cups (156 grams) all-purpose flour
- 1 cup (200 grams) granulated sugar
- 1/4 teaspoon salt
- 1/4 teaspoon cinnamon
- 1/2 teaspoon baking soda
- 5 tablespoons (70 grams) unsalted butter, melted
- 3 tablespoons (48 grams) peanut butter
- ½ cup (115 mL) low-fat buttermilk
- 1 large egg
Frosting
- 6 tablespoons (85 grams) unsalted butter
- 1/4 cup (64 grams) peanut butter
- 3 tablespoons (45 mL) buttermilk
- 2 cups (240 grams) powdered sugar
- 1/2 teaspoon vanilla extract
Instructions
- Prepare pan and preheat oven: Grease a 9x13-inch or 1-inch quarter sheet pan with cooking spray. Preheat your oven to 350°F (175°C) to ensure it is hot and ready when you finish the batter.
- Mix dry ingredients: In a large bowl, whisk together the all-purpose flour, granulated sugar, salt, cinnamon, and baking soda until well combined. This ensures even distribution of leavening and spices.
- Melt butter and peanut butter: In a small saucepan over low heat or using a microwave-safe dish, melt the unsalted butter and peanut butter together until smooth and fully combined, stirring frequently to avoid burning.
- Add wet ingredients: To the melted butter and peanut butter mixture, add the low-fat buttermilk and the large egg. Whisk thoroughly until the mixture is smooth and homogeneous.
- Combine wet and dry ingredients: Pour the wet ingredients over the dry ingredients. Stir gently but thoroughly until the batter is just combined, taking care not to overmix for a tender crumb.
- Bake the cake: Pour the batter into the prepared pan, spreading evenly. Bake in the preheated oven for 22 to 26 minutes. The cake edges will brown more than the center, and it may not pull away from the pan. Use a toothpick inserted in the center to check doneness—when it comes out with a few moist crumbs, the cake is done.
- Make the frosting: While the cake is still warm, prepare the frosting by adding the unsalted butter, peanut butter, buttermilk, and powdered sugar to a small saucepan. Heat over low heat, stirring frequently until the frosting is melted, smooth, and pourable.
- Finish with frosting: Remove the frosting from heat, stir in the vanilla extract, then immediately pour the warm frosting evenly over the warm cake. Spread it to the edges and allow it to set completely before slicing and serving.
Notes
- For best results, allow the cake to cool slightly before frosting to ensure the frosting sets properly.
- Use natural peanut butter for a less sweet, more intense peanut flavor; creamy peanut butter works best for a smooth texture.
- This cake can be stored covered at room temperature for up to 2 days or refrigerated for up to 4 days.
- To make slicing easier, chill the cake after the frosting has set.
- If desired, add chopped peanuts on top of the frosting for extra crunch.
