Preheat oven 375 degrees and spray 10 muffin tins with non-stick spray

In a small bowl combine flax and water and set aside for about 10 minutes

In a mixing bowl combine flours, baking soda, baking powder and salt

In a separate bowl whisk together sugar, bananas, melted butter and flax mixture

Add the liquid mixture to the flour mixture and fold together just until combined.

Divide between prepared muffin tins

Combine brown sugar, 2 tbsp spelt flour and cinnamon. Cut in butter with a fork and sprinkle evenly over muffin batter

Bake for 18 to 20 minutes, until toothpick inserted in centre comes out clean

Remove from oven and allow to cool 5 minutes before removing from tins