Preheat oven to 350 F. Grease a 9x5-inch loaf pan; set aside.
In a large bowl, beat bananas until mashed.
4 overripe bananas
Add butter and sugar, and beat until well-combined.
¼ cup salted butter, ½ cup granulated sugar
Mix in egg and vanilla.
1 large egg, 1 tablespoon vanilla
Add flour, baking soda, and salt; stir in until just incorporated.
1 ½ cups all-purpose flour, 1 teaspoon baking soda, ½ teaspoon salt
Bake for 45-55 minutes, or until a toothpick inserted in the center comes out clean. If the bread begins to brown too quickly, tent with aluminum foil.
Let cool in pan for 10 minutes, and then remove to a wire rack to finish cooling.
To make the glaze, add butter to a heavy saucepan.
¼ cup salted butter
Cook butter over medium heat until it starts to foam, stirring frequently.
Stop stirring, and let it continue to cook until amber brown.
Remove from heat, and stir in powdered sugar and enough milk to make glaze desired consistency. If your powdered sugar is lumpy, sifting it will help make the glaze smoother.
½ cup powdered sugar, 2-3 tablespoons milk
Drizzle over cooled banana bread.
Notes
Bananas: I like to use yellow bananas with brown spots. I don't use bananas that have turned black because they can be bitter or have an off taste to them.
Butter: You can also use unsalted butter + 1/4 teaspoon of salt if you prefer.
Vanilla: If you would like less vanilla flavor, you can reduce the vanilla to 1-2 teaspoons.