Preheat the oven to 350℉. Lightly spray donut pans with cooking spray and set aside.
In a medium bowl, mix together the flour, baking powder, baking soda and salt. Set aside.
In a large bowl, cream together the sugars and maple syrup until combined. Mix in the eggs, oil, bananas, yogurt and vanilla until smooth.
Slowly mix the dry ingredients into the wet ingredients until just combined.
Scoop the batter into a large ziplock bag and cut the tip off. Fill each donut cavity around ¾ full.
Bake in the preheated oven for around 15 minutes, or until a toothpick inserted comes out clean. Allow to cool in the pan for around 5 minutes, then transfer to wire racks to cool completely.
Cinnamon sugar: In a small bowl, mix together the sugar and cinnamon. Dip each donut in the melted butter, then dip the donut into the cinnamon sugar, making sure to coat both sides.
Notes
Storage: These donuts are best served warm, but if you have extras, store in an airtight container at room temperature for 1 day, or in the fridge for 2 days.
Use very ripe bananas for this recipe. This helps naturally sweeten the donuts, as well making the donuts have a more moist texture.
To pipe the batter into the donut pans, I like to use either a piping bag or a large freezer bag. To use the freezer bag, scoop the batter into the bag and cut a hole in the corner of the bag.