1 tsp. vanilla extract
2 1/2 tbsp. milk
4 cups powdered sugar
vanilla beans seeds
1 cup salted butter, at room temperature
Fluffy Vanilla Bean Frosting
1 large egg
1/2 cup packed light-brown sugar
1/2 cup granulated sugar
1/2 cup butter, softened
1/4 cup sour cream
1 cup mashed overripe bananas (about 2 large)
1/2 tsp. salt
1/2 tsp. baking soda
1/2 tsp. baking powder
2 cups all-purpose flour