Preheat oven to 350 degrees F and line 2 baking sheets with parchment paper.
In a large bowl, whisk together flour, xanthan gum, baking soda, salt, granulated sugar, and oats.
In a stand mixer, beat butter on medium speed until fluffy.
Add the brown sugar and beat just until creamed together.
Add the 2 eggs and vanilla. Beat for about 30 seconds on medium speed.
Now, gradually add the flour mixture to the butter mixture and mix until the dry ingredients are nearly absorbed.
Fold in raisins.
Using a large cookie scoop/cupcake scoop, scoop out dough in even amounts and roll into balls. Place on parchment paper and press down with hand to flatten to about 1/2 inch thick, being sure cookies are spaced about 2 inches apart.
Bake, one pan at a time, for about 14 to 16 minutes, or until edges are golden brown.
Remove pan from oven and allow cookies to rest for 5 minutes and then transfer cookies to a cooling rack. Enjoy!
