For the cake:
1 box or 432 grams of cake mix
3 ripe bananas, mashed
3 large eggs
1/2 cup or 120 ml vegetable oil
1 cup water
1 teaspoon vanilla extract
1/2 cup or 128 grams peanut butter
1/2 cup mini chocolate chips
Sprinkles (for decoration)
For peanut butter frosting:
1/2 cup unsalted butter, softened
1 cup creamy peanut butter
2 cups powdered sugar
1/4 cup milk
1 teaspoon vanilla extract
Preheat the oven to 350°F or 175°C and grease the 9x13-inch baking pan.
Combine the cake mix, mashed bananas, eggs, vegetable oil, water and vanilla extract and mix it well. Add peanut butter to the batter and mix until well combined.
Gently fold the chocolate chips in the batter.
Pour the batter into the baking pan and bake for 30-35 minutes in the preheated oven.
Allow the cake to cool and meanwhile prepare the frosting by combining softened butter, peanut butter, and powdered sugar. Add milk while beating the mixture on high speed until it becomes fluffy.
Frost the cake and add decoration as you like before serving.