Heat oven to 350°F and grease a donut pan well.
Whisk together the almond flour, protein powder, allulose, baking powder, cinnamon, and salt.
In a smoothie blender, combine the eggs, cottage cheese, milk, melted butter, vanilla, and apple cider mix.
Stir wet into dry just until combined.
Let the batter sit 5 minutes so the almond flour hydrates.
Transfer batter to a zip-top or piping bag and pipe into the donut cavities, about ¾ full.
Bake 14–17 minutes, until the tops spring back lightly.
Cool in the pan about 5 minutes, then move to a rack.
Mix the powdered allulose, milk, vanilla, and salt into a thin glaze.
Dip the tops of the slightly warm donuts and let the glaze set.