Mix together flour, cinnamon, cream of tartar, salt, and baking soda in a large mixing bowl.
Using your stand mixer and the paddle attachment, mix butter, granulated sugar, and brown sugar together until well blended. Add the egg, egg yolk, and vanilla extract. Mix on medium until well combined.
Slowly add the dry mixture to the wet mixture until they are combined.
Cover with plastic wrap and refrigerate for at least an hour.
Preheat your oven to 350°, and line a baking sheet with parchment paper and set aside.
Whisk together ½ cup of granulated white sugar and 4 tsp of cinnamon.
Scoop 1 tbsp of cookie dough into the cinnamon and sugar coating, roll it around until it is well coated, and place it on a lined cookie sheet.
Bake for 8-10 mins. or until they are golden brown.
Remove the cookies from the cookie sheet and allow them to cool completely.