Preheat the oven to 350 degrees.

In a medium sized mixing bowl, mash the bananas with a fork. Add the brown sugar, sugar, oil, vanilla, sour cream, and egg and mix well.

Add the remaining dry ingredients and stir until just combined. Don't over mix.

Spray the donut pans with nonstick baking spray. Pour the donut batter into a large ziplock bag and snip off one corner with scissors so that you can pipe the batter into the donut pan.

Bake at 350 degrees for about 8-10 minutes for mini donuts or 14-15 minutes for large donuts. Donuts will be ready when a toothpick inserted in the middle comes out clean or when you press on it slightly and it springs back.

Allow the donuts to cool and remove from the pan.

To prepare the glaze, bring the sugar, salt, butter, and milk to boil in a small saucepan over medium heat stirring constantly. Allow to boil one minute, while stirring.

Remove from the heat and stir in the vanilla.

Continue stirring for 3 minutes until the glaze is cool enough to use.

Pour the glaze into a shallow dish. Dip the top of each donut into the glaze and remove to a wire rack to cool and set up. If the glaze begins to set up before you are finished, heat it in the microwave for 5-10 seconds to warm it back up, taking care to make sure it's not too hot to work with before beginning again.