Preheat oven to 350 degrees and grease 4 mini loaf pans or 1 9x5 inch loaf pan.
In a medium bowl, combine the eggs, banana, sugar, oil, and yogurt.
Add in the flour, cinnamon, baking powder, and salt....stirring until just combined. *Do not overmix
In a small bowl, make the topping by combining the flour, brown sugar, and cinnamon.
Using your fingers or a fork, add in the butter and combine until crumbs form.
Pour batter evenly into prepared pan(s).
Sprinkle topping evenly on top of batter.
Place pan(s) in preheated oven and bake for about 45 minutes if using mini loaves, 60 minutes if large pan. *All ovens vary, so eye the bread a few minutes early and use a toothpick to test
Remove from oven and allow to cool for at least 3-5 minutes before removing from pan and slicing.