In a medium/small bowl, whisk together the gluten free flour, xanthan gum, ground cinnamon, baking soda, salt, and baking powder. Stir in the gluten free oats.

Add the melted butter, shortening, and light brown sugar to the bowl of a stand mixer fitted with a paddle attachment. Beat together until smooth.

Add the egg and vanilla extract and mix until light in color, creamy, and slightly thickened, about 1 minute.

Scrape down the bowl and add the flour/oat mixture to the bowl. Mix on medium-low speed until completely combined, scraping down the bowl as necessary. Add the raisins and fold in with a spatula or wooden spoon to incorporate. 

Cover and refrigerate for 6 hours or overnight. 

When ready to bake, preheat the oven to 350 degrees and line a baking sheet with parchment paper or a silicone baking mat. Use an OXO large scoop to scoop the dough. Roll the dough into balls and slightly flatten it to form a puck shape.

Bake in batches of 6-8 cookies at a time on a single sheet on the center rack for 12 minutes. Cool the cookies on the pan for at least 10 minutes before removing them from the pan to cool on a wire rack. (The cookies will look under-done when they first come out but will finish baking as they cool on the pan.

Bake the cookies for 12-14 minutes or until they’re golden brown around the edges. 

Allow the cookies to cool to room temperature on the baking sheet (they’ll harden slightly as they cool). Then, transfer the cookies to an airtight container and store them at room temperature for up to two days.