01 -
Preheat oven to 375°F and grease a 9x13 inch pan with non-stick cooking spray.
02 -
In a large bowl, cream together the sugar and butter. Beat in the Greek yogurt or sour cream, eggs, mashed bananas, and vanilla extract. Add the flour, baking soda, and salt, and mix until just moistened.
03 -
Spread the batter evenly into the prepared pan. Bake for 23-28 minutes, or until a toothpick inserted in the center comes out clean or with a few crumbs.
04 -
While the bars bake, heat the butter in a large skillet over medium heat. Simmer until it turns a delicate brown and releases a nutty aroma, watching carefully to avoid burning. Remove from heat immediately.
05 -
Whisk in the powdered sugar, vanilla extract, and 1 tablespoon of milk until smooth. Add more powdered sugar or milk as needed to reach desired frosting consistency.
06 -
Pour the warm frosting over the warm banana bread bars. Spread gently with the back of a spoon.