Preheat oven to 350°F. Line a baking sheet with parchment paper and set aside.
In a large bowl, whisk together flour, cream of tartar, baking soda, cinnamon, and salt.
In a stand mixer or using hand-held beaters, cream together the butter and sugar until light and fluffy. Add eggs and vanilla extract; mix until well combined.
Gradually add dry ingredients to wet ingredients and mix just until combined.
In a small bowl, mix together the sugar and cinnamon for the coating.
Use a small cookie scoop to portion dough, then roll into balls. Roll each ball thoroughly in the cinnamon sugar mixture.
Place dough balls 2 inches apart on the prepared baking sheet.
Bake for 8–10 minutes, until edges are set but centers are still soft.
Let cookies rest on the baking sheet for a few minutes before transferring to a wire rack to cool.