Preheat oven to 350.
Mix flour, sugar, baking soda, baking powder, and salt together in a bowl.
Blend in bananas, oil, and butter.
Stir in nuts, if using them.
Mix in cinnamon, nutmeg, and garam masala to taste.
Pour mixture into greased 8x8 pan (I just melt the butter in the pan, so that whatever remains after you pour the butter out greases the pan, and gives the bread a delicious buttery flavor.)
Bake for 30-35 minutes. Check with toothpick. If toothpick comes out clean, cake is done.