Preheat your oven to 350°F (175°C).

Cream together the softened butter and 1 ½ cups of sugar until light and fluffy.

Beat in the eggs one at a time, mixing well after each addition.

In a separate bowl, combine flour, cream of tartar, baking soda, and salt.

Gradually add the dry ingredients to the butter mixture, mixing until just combined.

In a small bowl, mix 3 tablespoons of sugar with 3 tablespoons of cinnamon.

Roll the dough into balls and coat them in the cinnamon-sugar mixture.

Place coated dough balls on ungreased baking sheets, spaced about 2 inches apart.

Bake for 10-12 minutes or until the edges are lightly golden.

Remove from the oven and let cool on the baking sheets for a few minutes before transferring to wire racks.