Mix together 3 overripe bananas, 1 tsp vanilla extract, 1 egg, ¾ cup brown sugar, and 1 stick browned butter
In a separate bowl, combine 2 cups all-purpose flour, 1 tsp baking soda, and ¼ tsp salt
Combine wet and dry ingredients, then fold in ⅔ cup chocolate chips
Pour batter into a greased baking pan
Prepare crumble by mixing ¼ cup brown sugar, 2 tbsp melted butter, ¼ tsp cinnamon, and 3-4 tbsp all-purpose flour until crumble consistency is reached
Sprinkle crumble topping over batter
Bake at 350 degrees for 30 minutes uncovered
Cover with foil and bake for an additional 20 minutes until fully cooked
