Preheat oven to 300 degrees.
In a large mixing bowl, blend sugars with electric mixer. Add butter and mix to form a grainy paste.
Scrape down sides of bowl with a spatula. Add vanilla and eggs. Mix at medium speed until light and fluffy.
In a medium bowl, use a fork to blend oat flour, xanthan gum, baking soda, and salt. Break up any lumps. Then add oats and stir until combined.
Add the flour mixture into the wet mixture. Add chopped walnuts, chocolate chips, and butterscotch chips. Mix on low speed until combined. Do not overmix.
Drop rounded tablespoons onto an ungreased cookie sheet. Be sure not to make them too big or too close together, as these cookies spread a bit.
Bake at 300 degrees for 16-20 minutes, until cookies are light golden brown.