Only 3 ingredients for this easy and delicious cake.   Easy Banana Cake Ingredients 1 Box yellow cake mix 4 to 5 over ripe bananas (smashed) pecans Sliced bananas topping (Optional) 2 to 3 bananas 1/4 cup lime juice Dots of butter Frosting (optional) 4 oz cream cheese, softened 4 tablespoons unsalted butter, softened 2