Whisk flour, xantham gum, cream of tartar, baking soda, and salt together in small bowl.
Beat sugar and melted butter together.
Add eggs and vanilla to butter mixture until well combined.
Add dry ingredients to wet ingredients and mix until just combined.
If dough is too sticky, cover and refrigerate for one hour.
Preheat oven to 400°F and line baking sheets with parchment paper.
Combine sugar and cinnamon in small bowl for rolling.
Use a cookie scoop to scoop a ball of cookie dough. Roll in cinnamon sugar mixture and place on baking sheet. Press down gently, to slightly flatten.
Bake smaller cookies for 7-8 minutes or larger cookies for 9-10 minutes.
Transfer to a cooling rack.