This is the recipe I've been using most often.
Grandma Cookhill’s Three Bowl Bread.
Banana Bread
1/3 cup softened butter
2/3 cup sugar
1 egg
1 3/4 cup flour
1 1/2 tsp baking powder
1/4 tsp baking soda
1 tsp cinnamon
3 very ripe bananas
In a large bowl, cream together butter and sugar. Mix in egg.
In another bowl, sift together flour, baking powder, baking soda, and cinnamon. Mash bananas. Alternately, add flour mixture and banana mixture to the butter-sugar-egg bowl. Stir until well mixed. Pour into 8 by 4 bread pan and bake at 350 degrees for one hour.