Mix together the butter and sugar until smooth, and then add the eggs, smashed up bananas and vanilla. Blend until mixed together really well. Next, in a separate bowl combine the dry ingredients. While the mixer is still on, slowly add the flour mixture and mix until smooth.
Spray a loaf pan to prevent sticking. Recipe makes one loaf.
Pour banana bread batter into the loaf pan and set aside. The Streusel (makes enough for 2 loaves of bread)- ¼ cup sugar ¼ cup brown sugar ½ cup flour ¾ teaspoon cinnamon ¼ cup butter or margarine melted.