Preheat the oven to 350 F (175 C) and line baking sheets with parchment paper.
In a large bowl, cream together softened butter and granulated sugar until light and fluffy.
Beat in the eggs, one at a time, and stir in vanilla extract.
In a separate bowl, whisk together all-purpose flour, cream of tartar, baking soda, and salt.
Gradually add the dry ingredients to the wet ingredients, mixing until a soft dough forms.
In a small bowl, combine the sugar and ground cinnamon for the coating.
Shape the dough into tablespoon-sized balls and roll each ball in the cinnamon sugar mixture.
Place the coated dough balls on the prepared baking sheets, leaving space between each.
Bake for 10-12 minutes or until the edges are set and the centers are slightly soft.
Allow the cookies to cool on the baking sheets for a few minutes before transferring them to a wire rack to cool completely.
