Preheat the oven to 350°F (180°C) and lightly grease a baking sheet or line it with a silicone mat.
Whisk together gluten-free oats, almond flour, potato starch, baking soda, and salt in a medium bowl. Set aside.
Beat the egg with the peanut butter and sugar in a large bowl with a hand whisk. Add vanilla extract.
Stir in the flour and mix until get a cookie dough. The dough is a little bit sticky.
Place cookie dough balls on the baking sheet and press down slightly.
Bake for 12 minutes. Keep in mind that all ovens are different.
Let cool before removing.
Notes
Cookies can be stored in an airtight container at room temperature for up to 5 days. You can also freeze the cookies once they have cooled completely, in an airtight container or freezer bag for up to 3 months. When you are ready to enjoy them, warm them slightly in a medium oven before eating.