1. Preheat oven to 350°F. Grease a 9×13-inch baking dish and set aside.
2. In a large bowl, cream together the butter and sugar until light and fluffy.
3. Add the eggs, sour cream, and vanilla extract, mixing well.
4. Gradually blend in the flour, baking soda, and salt.
5. Stir in the mashed bananas until just combined.
6. Pour the batter into the prepared baking dish, smoothing the top with a spatula.
7. Bake for 25-35 minutes, or until a toothpick inserted into the center comes out clean.
8. Allow the cake to cool completely.
9. For the frosting, beat together the butter and cream cheese until smooth.
10. Add the vanilla extract, powdered sugar, and heavy cream, beating until creamy.
11. Spread the frosting over the cooled cake.
12. Slice and serve.

Prep Time: 20 minutes | Cooking Time: 30 minutes | Total Time: 50 minutes + cooling | Servings: 18 pieces”