In a small bowl, pour hot water over the raisins until completely covered. Set aside for about 5 minutes, until the raisins have plumped up. Then drain the water.
In a large mixing beat together the softened butter, light brown sugar, sugar and orange zest until a bit fluffy. You can also use a drop of doterra Wild Orange essential oil if you don't have a orange on hand.
Add in the egg and vanilla and mix until combined.
In a separate mixing bowl, whisk together the dry ingredients: gluten free flour blend, xanthan gum if using, baking powder, baking soda, salt and cinnamon. Then pour mixture into the wet butter mixture.
Use a rubber spatula to finish mixing it all together until it becomes a smooth dough. It's okay if the dough is sticky looking, that's normal.
Add in the oats and raisins and mix with a rubber spatula until combined.
Place saran wrap over the bowl and chill the cookie dough in the fridge for about 30-60 minutes.
When there is about 10 minutes left in the chilling process, preheat the oven to 350ºF and line large baking sheets with silicone baking mats or parchment paper.
Once the dough is chilled, use a cookie or ice cream scoop to scoop individual balls onto the lined baking sheets. Leave about 1 inch between the cookies.
Bake the oatmeal cookies for 10-12 minutes or until they are light golden brown around the edges. You want the cookies to look underbaked to get that soft and chewy texture.
Remove from oven and allow cookies to cool for a few minutes on the cooking sheet, then transfer to a wire baking rack to cool.