Preheat your oven to 375°F (190°C) and line baking sheets with parchment paper.

In a large mixing bowl, cream together unsalted butter and granulated sugar until light and fluffy.

Add the eggs one at a time, mixing thoroughly after each addition.

In a separate bowl, whisk together flour, cream of tartar, baking soda, and salt. Gradually add to wet ingredients.

Roll the dough into 1.5-inch balls and set aside.

Mix the granulated sugar and ground cinnamon in a small bowl; roll each dough ball in the mixture.

Place the dough balls on baking sheets about 2 inches apart and bake for 8-10 minutes.

Allow cookies to cool on the pan for about 5 minutes before transferring to a wire rack.