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Decadent Peanut Butter Cake Recipe
Emily

Peanut Butter Cake

A rich and moist peanut butter cake layered with creamy peanut butter frosting. Perfect for birthdays, gatherings, or whenever you crave a decadent homemade dessert.
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Prep Time 25 minutes
Cook Time 35 minutes
Total Time 1 hour
Servings: 12 slices
Course: Dessert
Cuisine: American
Calories: 560
Ingredients Equipment Method Notes

Ingredients
  

  • 1⅔ cups (210 g) all-purpose flour
  • 3 tbsp (24 g) cornstarch
  • ½ tsp baking soda
  • 2 tsp baking powder
  • ½ tsp salt (omit if using salted butter)
  • ⅓ cup (80 g) unsalted butter, room temperature
  • ⅓ cup (75 g) unflavored vegetable oil
  • ½ cup (100 g) white granulated sugar
  • ¾ cup (150 g) light soft brown sugar
  • ⅔ cup (150 g) smooth unsweetened creamy peanut butter
  • 3 large eggs, room temperature
  • 1½ tsp vanilla extract
  • 1 cup (225 g) buttermilk, room temperature
  • 1½ cups (340 g) unsalted butter, room temperature (for frosting)
  • 3 cups (375 g) powdered sugar (confectioners’ sugar)
  • 2 tsp vanilla extract (for frosting)
  • ½ cup (120 g) whipping or heavy cream, room temperature
  • ½ tsp salt
  • 1 cup (250 g) smooth unsweetened creamy peanut butter (for frosting)

Equipment

  • Mixing bowls
  • Hand or stand mixer
  • Measuring cups and spoons
  • 8-inch round cake pans
  • Parchment paper
  • Spatula
  • wire racks
  • cake scraper and offset spatula

Method
 

  1. Preheat oven to 180°C (350°F). For fan or convection ovens, reduce to 160°C (320°F). Grease and line two 8-inch cake pans.
  2. Cream together the butter, oil, sugars, and peanut butter for about 3 minutes until light and creamy.
  3. Add eggs one at a time, then mix in vanilla and buttermilk until fully combined.
  4. Fold in flour, cornstarch, baking soda, baking powder, and salt. Do not overmix.
  5. Divide batter into pans, tap to release air bubbles, and bake for 30–35 minutes or until a toothpick comes out clean.
  6. Cool cakes in pans for 15–20 minutes, then transfer to wire racks to cool completely.
  7. For frosting, mix all frosting ingredients on low until blended, then beat on medium-high for 10 minutes.
  8. Assemble cake: level layers, spread frosting between, stack, and frost top and sides. Smooth and decorate.

Notes

For extra flavor, sprinkle chopped roasted peanuts or drizzle melted chocolate over the frosted cake. This cake stores well covered at room temperature for up to 2 days or in the fridge for up to 5 days. Bring to room temperature before serving for the best texture.