Preheat your oven to 350°F (175°C).
In a large bowl, cream together the softened butter and 1 ½ cups sugar until light and fluffy.
Beat in the eggs, one at a time, mixing well after each addition.
In a separate bowl, whisk together flour, cream of tartar, baking soda, and salt.
Gradually add the dry ingredients to the wet mixture, stirring until well combined.
In a small bowl, mix 3 tablespoons sugar with 3 teaspoons cinnamon.
Roll the dough into 1-inch balls and then roll them in the cinnamon-sugar mixture.
Place the coated dough balls on ungreased baking sheets, spacing them 2 inches apart.
Bake in the preheated oven for 10-12 minutes, or until the edges are lightly golden.
Allow to cool on the baking sheets for a few minutes before transferring them to wire racks to cool completely.