Go Back
–+ servings
A slice of Banana Oatmeal Sheet Cake topped with Creamy Peanut Butter Frosting and chopped peanuts on a small plate next to the remainder of the cake in a baking dish on a cooling rack and a glass of milk and a fork
Print Recipe
3 from 1 vote

Banana Oatmeal Sheet Cake with Peanut Butter Frosting

Moist and delicate Banana Oatmeal Sheet Cake with a rich and fluffy Peanut Butter Frosting.
Prep Time15 minutes
Cook Time30 minutes
Course: Dessert
Cuisine: American
Servings: 12 slices
Author: Joanie Zisk

Ingredients

For The Cake

  • 1 cup old-fashioned oats
  • 1 1/2 cups boiling water
  • 1 1/3 cup all-purpose flour
  • 1 teaspoon baking soda
  • 1/2 teaspoon salt
  • 12 tablespoons butter softened
  • 1 cup sugar
  • 1 cup packed brown sugar
  • 2 bananas peeled and mashed
  • 2 large eggs
  • 1 teaspoon vanilla

For The Frosting

  • 1/2 cup smooth peanut butter
  • 4 ounces cream cheese
  • 1 1/2 tablespoons butter
  • 1 teaspoon vanilla
  • 3 tablespoons heavy cream or milk
  • 2 1/2 cups powdered sugar sifted

Instructions

  • Combine the oats and the boiling water and let stand for at least 20 minutes.
  • Preheat the oven to 350 degrees F.
  • Grease a 13x9-inch baking pan.
  • Whisk together in a large bowl the flour, baking soda and salt. Set aside.
  • In a medium bowl, beat the butter and the sugars together at high speed for 3 minutes.
  • Add in the mashed bananas and beat for 2 minutes more.
  • Add in the eggs, one at a time beating after each addition.
  • Mix in the vanilla extract.
  • Beat in the oat mixture, then the flour mixture. Spoon the batter into the prepared pan and spread evenly.
  • Bake until a toothpick inserted in the center comes out clean, about 30 minutes.
  • Let cool.

To Make The Peanut Butter Frosting

  • In a medium bowl, beat the peanut butter, cream cheese, butter, vanilla and milk together until blended.
  • Add in 1/3 cup of the powdered sugar and mix. Continue to add in the powdered sugar 1/3 cup at a time until it is all added mix until the frosting is smooth.
  • If the frosting is too stiff, add additional milk or cream.