Preheat oven to 350°. In a medium bowl, whisk together eggs, almond milk, Greek yogurt, avocado oil, coconut sugar, maple extract, baking powder, and protein powder. Whisk until no clumps remain.
Add the whole wheat pastry flour, and stir until just combined. Don't overmix.
Grease a donut pan, and fill 12 donut molds about 3/4 full of batter (it's okay to be messy!). Bake in the preheated oven for 10-12 minutes, until just beginning to turn golden on the edges. These are easy to overbake, so check them at 10 minutes and every minute afterward.
Remove the donuts and allow them to cool. While the donuts are cooling, make the maple glaze. Whisk together the glaze ingredients until smooth, and set aside.
Once the donuts have cooled, dip the donuts in the glaze so the top half of each donut is covered. Shake the excess off, and set on a cooling rack. Allow the glaze to harden, then eat!