01 - Preheat the oven to 350°F and line two baking sheets with parchment paper.
02 - Whisk together the flour, cream of tartar, baking soda, and salt in a medium bowl; set aside.
03 - Beat the butter and 1 1/2 cups granulated sugar in a large bowl until light and fluffy, about 2 to 3 minutes.
04 - Incorporate eggs one at a time, beating well after each addition, then mix in vanilla extract.
05 - Gradually add the dry ingredients to the wet mixture, mixing just until combined.
06 - Stir together sugar and cinnamon in a small bowl for coating.
07 - Scoop tablespoon-sized portions of dough, roll into balls, and coat completely in the cinnamon sugar mixture.
08 - Place dough balls 2 inches apart on the prepared baking sheets.
09 - Bake for 9 to 11 minutes until edges are set and centers appear slightly underbaked.
10 - Let cookies cool on the baking sheet for 5 minutes before transferring to a wire rack to cool completely.