01 -
Lightly butter or spray a nonstick donut pan and set it aside. Preheat the oven to 350 F/180 C.
02 -
In a mixing bowl, whisk together the flour, cinnamon, baking powder, baking soda, and salt.
03 -
In a separate bowl, whisk together the buttermilk, melted butter, mashed banana, sugar, brown sugar, sour cream, oil, and vanilla extract.
04 -
Whisk the wet ingredients into the dry ingredients until just combined.
05 -
Pipe the batter into the donut pan.
06 -
Bake on the middle rack for 11-12 minutes, or until the tops spring back when touched.
07 -
Let the pan cool on a wire rack, then flip over and gently remove the baked donuts.
08 -
To make the glaze, melt the butter and brown sugar until smooth. Add in the milk and bring to a simmer. Then remove the pan from the heat and whisk in the powdered sugar and vanilla until well combined. Transfer to a bowl and set aside to cool for 10-12 minutes. It will seem very thin at first but will thicken as it cools!
09 -
To caramelize the bananas, melt the butter in a saucepan over medium heat. Sprinkle the sugar and cinnamon over the butter then add the banana slices to the pan. Gently flip the bananas after 2 minutes and cook for 1 minute longer.
10 -
Dip the tops of the donuts in the glaze. If the glaze is running off quickly, it needs more time to cool. If the glaze is too thick and it doesn't stick to the top, gently heat it in the microwave in 10-15 second increments until the proper consistency is reached.
11 -
Spoon the caramelized banana slices into the center of the donut and enjoy!