Preheat oven to 350 degrees and prepare baking sheets
In a mixing bowl, cream together butter, sugar, and vanilla. Add egg yolk and mix well.
In a separate bowl, mix together the dry ingredients. Flour, baking soda, salt, and cream of tartar.
Add dry ingredients to the wet, until combined, and fold in chocolate chips.
In a small bowl, mix together sugar and cinnamon. Roll cookie dough into balls and roll them in the cinnamon-sugar until the cookie dough is fully coated, and place them on a baking sheet.
Bake for 8–10 minutes until edges are just set and centers look slightly underdone. Let cool on the pan for a few minutes before transferring.