A hearty loaf of banana bread is an excellent way to use up a pile of leftover bananas, but sometimes you want a lighter option. These tender banana muffins are crowned with a delightfully crunchy cinnamon crumb topping that lends to their addictive nature. The easy recipe, which doesn't require any special equipment – just a couple of bowls – was adapted from one originally developed by a 9-year old named Meghan Cwikla. With it, she won the junior division at the 1997 State Baking Contest…