Preheat the oven to 350ºF and line a large baking sheet with parchment paper. In a large mixing bowl, mix the butter and sugar.
Next, add the egg and vanilla extract and stir again. Then add in the oat flour, baking soda, and salt. Mix well until the dough looks uniform, with no visible clumps. Fold in the oats and chocolate chips. (If you prefer to use raisins, you may want to also add ½ teaspoon of ground cinnamon.)
Use a heaping tablespoon or cookie scoop to scoop the dough onto the prepared pan. (My cookie scoop is roughly 1 ½ tablespoons and yields 24 cookies from this batch.) Leave 1 to 2 inches of space between the cookie dough balls to allow for spreading.
Bake at 350ºF for 8 to 10 minutes. For cookies with a soft center, remove the cookies at 8 minutes and let them cool completely on the pan. For crispier cookies, let them bake for 10 minutes.
These gluten-free cookies will feel more fragile when you serve them warm, but they will firm up as they cool. Store them in an airtight container in the fridge for the best shelf life; oat flour will continue to dry out if you store these at room temperature for too long. You can also freeze the cookie dough and bake it later! (See notes for tips.)
Notes
Nutrition information is for 1 of 24 cookies without the chocolate chips or raisins. This information is automatically calculated using generic ingredients, so it's just an estimate, not a guarantee.Gluten-Free Note: Oats are naturally gluten-free but can be contaminated during processing. If needed, shop for certified gluten-free oats. You can also make your own oat flour by simply grinding rolled oats in a dry blender.Butter Note: I love using salted butter in cookie recipes for extra flavor. However, unsalted butter will also work. For a dairy-free cookie, swap this for vegan butter (like Miyokos brand) or refined coconut oil, adding zero coconut flavor.Freezer Tips: To freeze cookie dough for later, drop the dough balls on a lined plate or baking sheet as if you're about to bake them. Place this in the freezer on a flat shelf to freeze for 1 hour. Then, transfer to a freezer bag or airtight container and freeze for up to 3 months. To bake the frozen cookie dough, let the dough balls thaw on the pan for about 20 minutes as the oven preheats to 350ºF. Flatten them slightly if you want them to spread out (frozen dough won't spread as much as freshly made dough). Bake for 8 to 10 minutes and let the cookies cool on the pan before enjoying.