First Step: Prepare Baking Equipment and Oven
Preheat your oven to 350°F (180°C). Grease your donut molds with nonstick spray or butter to prevent sticking and ensure easy removal after baking.

Second Step: Mix Dry Ingredients
In a medium bowl, whisk together the flour, light brown sugar, salt, and baking powder to remove lumps and evenly distribute ingredients for a smooth batter.

Third Step: Combine Wet Ingredients
In a separate bowl, mash the overripe bananas until mostly smooth. Add melted butter and the egg, mixing until well combined. For vegan options, substitute the egg with flaxseed meal and milk with a plant-based alternative.

Fourth Step: Combine Wet and Dry Mixtures
Gently fold the wet banana mixture into the dry ingredients, stirring just until combined. Avoid over-mixing, which can make the donuts heavy and dry. The batter should be moderately thick and moist.

Fifth Step: Fill Donut Molds and Bake
Spoon or use a piping bag to fill the prepared molds about ¾ full to allow room for rising. Bake for 15–20 minutes. Test doneness with a toothpick inserted into the donuts if it comes out clean, they are done. Donuts should spring back lightly when pressed.

Sixth Step: Cool Donuts
Allow the donuts to cool in the molds for about 10 minutes before carefully removing them. Transfer to a wire rack to cool completely, so they hold their shape and avoid sogginess.

Seventh Step: Prepare Brown Butter Icing
Melt butter in a saucepan over medium heat, swirling until it foams and brown bits form, about 5 minutes. Remove from heat and let cool slightly. Whisk in powdered sugar and vanilla until smooth. Add milk or heavy cream tablespoon by tablespoon until you reach your desired consistency.

Final Step: Ice and Serve
Dip the cooled banana donuts into the brown butter icing or drizzle it over the tops if you prefer. Allow the icing to set slightly before serving. For a tangier option, prepare a cream cheese glaze instead. Enjoy fresh, or store as suggested.