Mash bananas in a large mixing bowl. Add sugar and lightly beaten egg. Stir in melted, cooled butter. Measure in the flour, sprinkle over the baking powder, baking soda and salt, then stir in to mix by gently folding. Do not over mix or beat.
Bake for 20 minutes or until a tester inserted in the center of a muffin comes out clean.
Recipe by Just a Smidgen at https://justasmidgen.com/2013/09/18/best-banana-muffins/