In a small bowl, combine all of chai spice mix ingredients. Stir to combine and set aside.
In a large bowl, preferably a stand mixer, combine room temperature butter, sugar and brown sugar for 2-3 minutes until well combined and slightly fluffy.
Add egg and vanilla extract and stir until combined.
Add gluten free flour blend, salt, baking soda, cream of tartar, and 2 teaspoon of chai spice mix. Combine until everything is mixed together. Cover dough with plastic wrap and refrigerate for at least 1 hour.
Preheat oven to 375 deg. F and prepare two baking sheets by lining with parchment paper or silicon mat.
Remove dough from refrigerator. Add 3 tbs sugar to the remaining chai spice mix and stir until mixed. Shape dough into balls, (about the size of a golf ball) and gently roll in the remaining chai spice sugar mix until coated all the way around the ball. Place on a cookie sheet about 1 ½ - 2 inches apart, repeating until the dough is gone.
Bake for 10-11 minutes, being careful not to overbake as you want them slightly chewy. Remove from oven and cool, storing any leftovers in an air-tight container.