Preheat oven to 350 degrees F. Line two baking sheets with parchment paper, a silicone baking mat, or non-stick cooking spray.
Add cake mix 1 teaspoon cinnamon, and cream of tartar to a large mixing bowl. Stir to combine.
Add eggs vanilla, and oil to dry ingredients and mix with a wooden spoon until completely combined.
Let dough rest for 10 minutes.
Meanwhile, mix the sugar and 2 teaspoons cinnamon in a small dowl.
Once the cookie dough is ready, use a cookie scoop or tablespoon to portion the dough. Roll the dough into 1-inch balls and then roll the balls in cinnamon-sugar until coated.
Place coated dough balls on prepared baking sheets, leaving 2-inches between cookies. They will spread.
Bake for about 12 minutes until the edges are slightly set. The cookies will still look puffy and soft.
Remove from oven and allow to cool for 5 minutes on the baking sheet. Then transfer the cookies to a wire rack to cool completely.
Notes
Store extra cookies in an airtight container for up to 2 weeks or freeze for several months.