This coffee cake is moist and tender, with a subtle banana flavor. My family loves the oatmeal streusel topping. If you like nuts in your topping, stir in a cup of chopped, toasted pecans or walnuts after cutting the butter into the dry ingredients. It's delicious while still warm, but the banana flavor intensifies if allowed to cool several hours. Also, for a different variation, I sometimes add a cup of chopped, toasted pecans or walnuts to the batter and frost with cream cheese frosting in place of the streusel.