Sift together the flours, salt, baking powder and baking soda. Add in the flaxseed, cinnamon and sugar and set aside. Combine the buttermilk, vanilla, butter extract and oil. Slowly stir in the mashed bananas and then the agave until all is combined. Pour the wet ingredients into the dry ingredients and stir just until it comes together. If you over-mix then the donuts will be too chewy. Place donut batter into greased donut pan and bake at 350 for 10-15 minutes depending on the size donut pan you have.
Recipe by Kitchen Belleicious at https://kitchenbelleicious.com/2012/08/27/whole-wheat-flaxseed-banana-donuts/