Step 1

Preheat oven to 350°. Line an 8×8 baking dish with foil and spray with cooking spray. Set aside

Step 2

In bowl of stand mixer combine melted (or browned) butter and sugar. Mix until combined. Add in egg and vanilla and continue mixing until incorporated. Stir in salt, flour and banana until batter is smooth and even. Spread in prepared pan.

Step 3

Bake for 25-30 minutes until center is set.

Step 4

Transfer pan to wire rack to cool.

Step 5

Frost the blondies when they are mostly cooled.

Step 6

In a medium saucepan melt butter. Add brown sugar and milk and stir until mixture comes to just a boil. Remove from heat, allow to cool for 5 minutes.

Step 7

Stir in powdered sugar with a whisk.

Step 8

Spread on top of blondies and allow frosting to set and blondies to cool completely before cutting into squares.