Preheat oven to 350F and spray a regular size 9x5 loaf pan with some non stick spray.
In a bowl whisk eggs and add in the 2 Tbsp of brown sugar, mix in the mashed bananas, apple sauce, milk and vanilla.
Stir in the flour, baking powder and cinnamon, mix well and then pour batter into the loaf pan.
In a small bowl mix the 1/4 cup flour, 1/4 cup brown sugar and 1 tsp of cinnamon together, add to the softened butter and mix till a crumb forms, if it is still too sticky try adding a bit more flour.
Sprinkle the crumble over top of the batter and then bake in the oven for 50 minutes, check that the loaf under all the crumble is baked through.
Let cool then carefully cut into 10 slices, yes the crumble can be tricky and you will likely lose some while cutting into pieces but I just added my fallen pieces to my serving.