Preheat oven to 375ºF and grease or line a loaf pan; set aside.
In a large bowl, beat eggs, yogurt, bananas, maple syrup, and vanilla. Mix in flour, oats, nutmeg, and baking powder. Stir until combined. Pour batter into prepared loaf pan and set aside.
In a separate bowl, combine oats, flour, brown sugar, and peanut butter and mix until it resembles a coarse crumb. Sprinkle on top of batter.