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Banana Peanut Butter Sheet Cake Recipe

Banana Peanut Butter Sheet Cake Recipe

This Banana Peanut Butter Sheet Cake Recipe combines mashed bananas, creamy peanut butter, and simple ingredients into a soft, delicious cake.
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Prep Time 15 minutes
Cook Time 30 minutes
Total Time 45 minutes
Course Dessert
Cuisine American
Servings 12 slices
Calories 320 kcal

Equipment

  • Large mixing bowl
  • Medium mixing bowl
  • Hand mixer or whisk
  • 9x13-inch baking pan
  • Parchment paper or nonstick spray
  • Measuring Cups and Spoons
  • Rubber spatula
  • Cooling rack
  • Offset spatula (for frosting)

Ingredients
  

For the Cake:

  • 3 ripe bananas mashed, about 1 ¼ cups
  • 1/2 cup creamy peanut butter
  • 1/2 cup unsalted butter softened
  • 1 cup granulated sugar
  • 1/2 cup brown sugar
  • 2 large eggs room temperature
  • 1 teaspoon vanilla extract
  • 2 cups all-purpose flour
  • 1 teaspoon baking soda
  • 1/2 teaspoon salt
  • 1/2 cup milk room temperature

For the Peanut Butter Frosting:

  • 1/2 cup creamy peanut butter
  • 1/4 cup unsalted butter softened
  • 2 cups powdered sugar
  • 2 –3 tablespoons milk
  • 1 teaspoon vanilla extract
  • Pinch of salt optional, enhances flavor

Instructions
 

Step 1: Prepare the Oven and Pan

  • Preheat your oven to 350°F (175°C). Grease a 9x13 inch pan or line it with parchment paper for easy removal. I like leaving a little overhang so I can lift the cake out cleanly.

Step 2: Cream Butter and Sugar

  • In a large bowl, beat together softened butter, granulated sugar, and brown sugar until light and fluffy. This step is key—it creates a soft, airy base for your cake.

Step 3: Add Eggs and Vanilla

  • Add the eggs one at a time, mixing well after each addition. Stir in the vanilla extract. The mixture should look smooth and slightly creamy.

Step 4: Add Banana and Peanut Butter

  • Mix in the mashed bananas and peanut butter until fully combined. The batter will look slightly thick and creamy with a rich aroma.

Step 5: Mix Dry Ingredients

  • In a separate bowl, whisk together flour, baking soda, and salt. This ensures even distribution and prevents clumps.

Step 6: Combine Wet and Dry

  • Add the dry ingredients to the wet mixture in batches, alternating with milk. Start and end with the dry ingredients. Mix gently until just combined—don’t overmix.

Step 7: Bake

  • Pour the batter into your prepared pan and smooth the top. Bake for 28–30 minutes, or until a toothpick inserted in the center comes out clean.

Step 8: Cool Completely

  • Let the cake cool fully in the pan before frosting. This prevents the frosting from melting too much.

Step 9: Make the Frosting

  • Beat peanut butter and butter until smooth and creamy. Add powdered sugar, vanilla, and milk gradually. Beat until light, fluffy, and spreadable.

Step 10: Frost and Serve

  • Spread the frosting evenly over the cooled cake. Slice into squares and enjoy.

Notes

  • Use overripe bananas with brown spots for maximum sweetness
  • Make sure ingredients are at room temperature
  • Don’t overmix the batter—it can make the cake dense
  • Check doneness early to avoid overbaking
  • Let the cake cool fully before frosting
Keyword Banana Peanut Butter Sheet Cake Recipe