Preheat the oven to 350°F (175°C). Grease a 9x13 inch baking dish.
In a medium bowl, whisk together flour, baking soda, and salt. Set aside.
In a large bowl, cream together the butter and sugar until light and fluffy. Beat in the eggs one at a time.
Stir in the mashed bananas, sour cream, and vanilla extract. Gradually add the dry ingredients, mixing until just combined.
Pour the batter into the prepared baking dish and spread evenly.
Bake for 45 minutes, or until a toothpick inserted into the center comes out clean. Allow the cake to cool completely.
To make the frosting, beat the cream cheese and butter together until smooth. Gradually add powdered sugar and vanilla extract, beating until the frosting is light and fluffy.
Spread the cream cheese frosting over the cooled cake. Serve and enjoy!
Notes
You can add walnuts or chocolate chips to the batter for added flavor and texture. Store the cake in the refrigerator for up to 3 days.