1. Preheat your oven to 350F. Line a 9×9 pan with parchment paper and spray with coconut oil cooking spray.
2. In a large mixing bowl, combine the flour, baking powder, cinnamon, salt and coconut sugar together.
3. In another mixing bowl, smash the ripe bananas until smooth. Stir in the melted butter, maple syrup, eggs and buttermilk until fully combined.
4. Add the wet ingredients to the dry ingredients bowl. Mix with a wooden spoon or rubber spatula until all the dry ingredients are incorporated.
5. Pour the batter into your prepared pan.
6. To make the crumble, combine all the ingredients in a bowl. Using your hands or a pastry cutter to break up the butter and combine it with the sugar and flour. When it forms a ‘crumble’ you are done. Sprinkle it in an even layer on top of the batter.
7. Place in your oven on the middle rack and bake for 45 minutes or until the middle is set. Remove from the oven and let cool for 30 minutes before slicing into.

To make a glaze – combine 1 tablespoon milk with 1/3 cup powdered sugar and a pinch of cinnamon. Drizzle on top, if desired.