Mix one stick butter with sugar. Add 2 tbsp oil, 1/4 tsp cinnamon, dash of nutmeg, 1 tsp vanilla, and 2 eggs.
Combine bananas, sour cream, and yogurt.
Mix flour with 1/2 tsp salt, 11/4 tsp baking powder, and 3/4 tsp baking soda
Mix all three mixtures together rapidly with a rubber spatula just until blended.
Bake 25-35 minutes in 4 mini loaf pans.