Preheat oven to 350 degrees Fahrenheit (175 degrees Celsius) and coat a six-cavity donut pan with non-stick spray.
Whisk together oat flour, protein powder, baking powder, and salt in a primary mixing bowl.
Combine applesauce, egg, 1/4 cup maple syrup, maple extract, and Greek yogurt in a secondary bowl until homogenous.
Fold the wet ingredients into the dry ingredients until just combined; do not overmix to avoid a rubbery texture.
Transfer the batter to a piping bag and distribute evenly into the donut pan cavities.
Bake for 10 to 12 minutes until the donuts are springy to the touch.
Allow donuts to cool in the pan for 5 minutes before transferring to a wire rack to cool completely.
Whisk the powdered erythritol, 2 tablespoons of maple syrup, and almond milk to create a smooth glaze.
Dip the top of each cooled donut into the glaze and immediately garnish with crumbled bacon bits.