Preheat the oven to 375 degrees and spray a 9×13 metal pan with non-stick cooking spray.
In a large bowl using a hand mixer, cream together the sugar and butter until combined. Add in the egg, sour cream, and vanilla and mix until combined.
Add in the flour, baking soda, and salt and mix until combined.
Using a spatula or spoon, fold in the bananas and chopped walnuts.
Spread batter into the sprayed baking pan and bake for 20-25 minutes or until a toothpick comes out clean. (Start the frosting as soon as the cake comes out of the oven)
For The Frosting
Heat a saucepan on medium heat and add the butter. Simmer until the butter starts to turn light brown. Keep an eye on it so it doesn’t burn. Remove from the heat and whisk in the powdered sugar, vanilla, and milk. You need to move pretty fast, you want the frosting to be hot when you spread it over the warm cake.
Pour frosting over warm cake and spread with a spatula and sprinkle more chopped walnuts on top.
Let the cake and frosting cool and come to room temperature before slicing.
Video
Notes
Use extra ripe bananas, the spottier, the better! Overripe bananas add natural sweetness and moisture to the cake.
Keep an eye on it so it doesn’t burn!
Store the cake at room temperature in an airtight container.
You can freeze the unfrosted cake (wrap tightly with plastic wrap and foil) for up to 2 months.
ADVERTISEMENT
