Preheat the oven to 350°F (175°C).

In a large bowl, cream together the softened butter and sugar until smooth.

Beat in the eggs one at a time.

Combine the flour, cream of tartar, baking soda, and salt; gradually add to the creamed mixture.

In a small bowl, mix 3 tablespoons of sugar with 1 tablespoon of cinnamon.

Roll dough into balls, then roll in the cinnamon-sugar mixture.

Place on ungreased baking sheets.

Bake for 8 to 10 minutes until lightly browned.

Allow to cool on the baking sheets for a few minutes before transferring to a wire rack.