Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.
In a large mixing bowl, cream together the softened butter and 1 ½ cups granulated sugar until light and fluffy.
Add in the eggs one at a time, mixing well after each addition. Stir in the vanilla extract until combined.
In a separate bowl, whisk together the flour, cream of tartar, baking soda, and salt.
Gradually add the dry mixture to the wet ingredients, mixing until just combined. Be careful not to overmix.
In a small bowl, combine ¼ cup granulated sugar with 2 tablespoons ground cinnamon for the rolling mixture.
Using a cookie scoop or tablespoon, scoop out portions of dough and roll them into balls. Roll each ball in the cinnamon-sugar mixture until fully coated.
Place the coated cookie dough balls on the prepared baking sheet, spaced about 2 inches apart.
Bake in the preheated oven for 10-12 minutes, or until the edges are set and the tops are slightly cracked. The cookies will continue to firm up as they cool.
Allow the cookies to cool on the baking sheet for about 5 minutes before transferring them to a wire rack to cool completely.
Notes
Arrange the cookies on a decorative platter and dust with a little extra cinnamon sugar for an enticing look. Serve with a glass of milk for the perfect pairing!