Preheat the oven to 350°F (175°C).

Lightly grease a donut pan with oil or nonstick spray.

In a bowl, mash the ripe bananas until smooth.

Add applesauce, maple syrup (or honey), vanilla extract, and eggs. Whisk until well combined.

In a separate bowl, mix the whole wheat flour, baking powder, cinnamon, and salt.

Pour the wet ingredients into the dry ingredients and stir gently until just combined. Do not overmix.

Spoon the batter evenly into the donut pan, filling each cavity about ¾ full.

Bake for 10–12 minutes, or until a toothpick inserted into a donut comes out clean.

Let the donuts cool in the pan for a few minutes, then transfer to a cooling rack to cool completely.

In a small bowl, whisk powdered sugar with milk and vanilla extract until smooth.

Dip the cooled donuts into the glaze, letting any excess drip off. Let the glaze set before serving.