Preheat your oven to 350°F (175°C). Line a large baking sheet with parchment paper.
Mix the almond flour, sweetener and Greek yogurt in a medium bowl until a thick dough forms. The consistency shoud be something you can scoop and roll into balls. If your mixture seems too wet, you can add a little more almond flour. Stir in the lemon zest until evenly mixed in.
Use a 1.5 tablespoon cookie scoop to scoop the dough. Roll the dough between your palms to form a round ball. Place onto prepared baking sheet. Repeat with remaining dough, spacing the donuts about 1 inch apart.
Bake for 20-30 minutes, or until the tops are light golden brown. The balls should also feel slightly firm and should not feel soft or mushy if you apply light pressure to the surface.
Let donuts fully cool before adding any optional glaze. Donuts are best consumed within a few hours after they are cooked. They will become more firm and less soft if they are left out too long. Store uneaten donuts in the fridge or freezer. I recommend reheating leftover donuts so that they become soft and chewy again.
