Preheat your oven to 350 degrees Fahrenheit.

Grease a 9 by 9 inch baking pan with a bit of butter or line it with parchment paper.

In a large mixing bowl, peel your ripe bananas and mash them until they are mostly smooth.

Pour in your melted butter and stir these together until they are well combined.

Stir in your brown sugar, the egg, and the vanilla extract.

In a separate smaller bowl, whisk together your all purpose flour, baking soda, and salt. Gently fold the dry ingredients into the wet banana mixture.

If you are adding chocolate chips or nuts, fold them in now.

Pour the batter into your prepared pan and smooth the top with a spatula.

Bake for about 25 to 30 minutes. You will know it is done when the edges are beginning to pull away from the pan and a toothpick inserted into the center comes out with just a few moist crumbs.

Let the brownies cool completely in the pan if you plan to top them with a brown butter glaze.