Preheat your oven to 350°F (175°C).
In a large mixing bowl, cream together the softened butter and 1 cup of granulated sugar until light and fluffy, about 2-3 minutes.
Beat in the large egg and 1 teaspoon of vanilla extract until well combined.
In a separate bowl, whisk together 2 cups of all-purpose flour, 1 teaspoon of baking soda, 2 teaspoons of cream of tartar, and 1/2 teaspoon of salt.
Gradually add the dry mixture to the wet mixture, mixing until just combined. Be careful not to overmix!
In a small bowl, combine 1/4 cup of granulated sugar and 2 teaspoons of ground cinnamon for coating.
Using a cookie scoop or your hands, form the dough into 1-inch balls and roll in the cinnamon-sugar mixture.
Place the coated cookie balls on a parchment-lined baking sheet, spacing them about 2 inches apart. Bake for 10-12 minutes, or until edges are lightly golden.
Allow the cookies to cool on the baking sheet for a few minutes before transferring to a wire rack to cool completely.