Preheat the oven to 350ºF (175ºC). Line 2-3 baking sheets with parchment paper. Set aside.
In a bowl, combine gluten-free flour, baking soda, baking powder, salt and cinnamon. Set aside.
In a large bowl, beat together granulated sugar, brown sugar and butter until creamed and smooth, about 2-3 minutes.
Then, add in the egg and vanilla, and mix until combined, about 1-2 minutes.
Stir in oats and raisins until fully incorporated.
Chill the dough for at least 20 minutes to let the flavors deepen.
Use a 3-tablespoon cookie scoop (or the yellow #20 scoop), to scoop the dough and place on the prepared baking sheets, leaving at least 2 inches between each ball. You may want to bake the cookies in batches. Leave the remaining cookie dough balls in the refrigerator until you’re ready to bake them.
Bake for 10-12 minutes at 350ºF (175ºC) on the center rack of the oven. If placing multiple baking sheets in the oven, switch their positions halfway through baking. Cool the cookies on the baking sheet for 5 minutes before transferring to wire racks to finish cooling.