Preheat heat oven to 350 degrees F. Prepare your donut pan, either spray or oil if using. I use my silicone donut pan and I don't use a spray but they do come out easier.
In a large bowl, mash banana until smooth with only a few lumps and add the remaining wet ingredients, vanilla, nut butter, almond milk and maple syrup.Stir well to combine.
Sift the dry ingredients over the wet ingredients and then mix to combine until the flour in well incorporated.
Transfer batter to a pastry bag or spoon the batter evenly into the donut pan.
Bake in the oven for 15-20 minutes until they are golden brown and a toothpick comes out dry when put in the thickest part.
Remove and put on cooling rack for about 5 minutes and then remove from mold. In the meantime, make the topping by mixing the sugar and cinnamon in a bowl.
Dip the donuts into the cinnamon sugar top and bottom. Serve and enjoy!
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