Preheat your oven to 350°F (175°C).

Grease a 9x13 inch baking pan with butter or cooking spray and dust with flour.

In a medium bowl, whisk together flour, baking soda, baking powder, and salt.

In a separate bowl, mash the ripe bananas until smooth with a few lumps.

In a large mixing bowl, beat the softened butter and granulated sugar together until light and fluffy, about 3-4 minutes.

Add the eggs one at a time, mixing well after each addition. Stir in the vanilla extract, mashed bananas, and sour cream until well combined.

Gradually add the dry ingredients to the wet mixture, mixing gently until just combined.

Fold in the chopped pecans using a spatula.

Pour the batter into the prepared baking pan and smooth the top with a spatula.

Bake for 30-35 minutes, or until a toothpick inserted into the center comes out clean.

Allow the cake to cool in the pan for about 10 minutes, then transfer to a wire rack to cool completely.

For the frosting, beat together cream cheese and butter until smooth. Gradually add powdered sugar and vanilla extract, mixing until combined. Add milk if needed for consistency.

Once the cake is completely cool, frost with the cream cheese frosting and serve.