Preheat the oven to 350°F (175°C) and give your donut pan a light spray with cooking spray to ensure easy removal after baking.

Whisk together in a mixing bowl the egg, milk, applesauce, sugar, and vanilla. Aim for a smooth and cohesive mixture that’s filled with delightful flavors.

Combine the dry ingredients: gradually add the flour, baking powder, ground cinnamon, and salt into the mixing bowl. Stir until the batter is completely smooth, creating a thick yet pourable consistency.

Spoon the batter into each cavity of the prepared donut pan, filling each almost to the top. Bake for 12-15 minutes, or until a toothpick inserted comes out clean—look for a light golden color.

Cool the donuts in the pan for a few minutes, then carefully transfer them to a baking sheet lined with parchment paper to cool completely, allowing them to maintain their fluffy texture.

Prepare the glaze by whisking together powdered sugar, ground cinnamon, applesauce, and water in a separate bowl. Mix until smooth, adding more water if necessary to reach the desired consistency.

Dip the tops of each cooled donut into the glaze, twisting gently to ensure an even coating. Let any excess drip off before placing them glaze-side up on the lined baking sheet.

Rest the glazed donuts for about 15 minutes, allowing the glaze to set and create a beautiful shine before serving.