Preheat oven to 375°Line two baking sheets with parchment paper.
In a large bowl, beat together butter, granulated sugar, and brown sugar on medium speed until smooth.
Add vanilla extract and egg and mix until fully combined.
Add flour, baking soda, baking powder, salt, cinnamon, oats to the mixture and mix until fully combined.
Mix in chocolate chips/raisins until fully combined.
Scoop dough with a greased 1½-tablespoons cookie scoop and place cookies 2 inches apart on a parchment-lined baking sheet.
Bake for 10–12 minutes until cookies start to turn golden brown.
Allow cookies to cool for 2–3 minutes before moving to a cooling rack.
Video
Notes
Soften your butter. Take the butter out of the refrigerator and allow to soften on the counter for 10-15 minutes.
It's super important to measure the gluten-free flour correctly. Use a measuring cup made for dry ingredients (not a Pyrex liquid measuring cup), and use the spoon and level method.
I also like to use Reynolds Kitchens Cookie Baking Sheets. It has a smart grid that makes it super easy to line up your cookies on your baking sheet. I buy it at Walmart.
To store: Place the cookies in an airtight container at room temperature for up to 1 week.
To freeze: Place the cookies in a single layer on a lined baking sheet until solid, about 1-2 hours. Transfer to an airtight container or Ziplock bag to store for up to 1 month.