1) Frosting:
1/2 cup butter
3 cups powdered sugar
1 1/2 teaspoons vanilla
3 tablespoons milk
2) Heat oven to 375 degrees.
3) Grease and flour a 13 x 9“ pan.
4) In a large bowl, beat together sugar, sour cream, butter, and eggs until creamy. Blend in bananas and vanilla.
5) Mix flour, baking soda, and salt in a separate bowl – then add to wet ingredients and blend together for one minute.
6) Spread batter evenly into pan. Bake 20 to 25 minutes or until golden brown. Cool slightly, and frost with frosting.
7) For the frosting, heat butter in a large saucepan over medium heat. Watch carefully until it reaches a medium brown color then turn off the heat, whisk in powdered sugar adding milk as it thickens then add in the vanilla.
8) Pour over the warm banana bread brownies immediately and smooth with a spatula.
9) Cool before cutting.