Preheat the Oven:

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

Make the Dough:

In a large mixing bowl, cream together the softened butter and granulated sugar until light and fluffy. Add the eggs one at a time, mixing well after each addition.

In another bowl, whisk together the flour, cream of tartar, baking soda, and salt. Gradually add the dry ingredients to the wet ingredients, mixing until just combined.

Prepare the Coating:

In a small bowl, mix the granulated sugar and ground cinnamon for the coating.

Shape the Cookies:

Use a cookie scoop or spoon to form 1-inch balls of dough. Roll each ball in the cinnamon-sugar mixture to coat evenly.

Bake:

Place the coated dough balls on the prepared baking sheets, spacing them about 2 inches apart. Bake for 8–10 minutes, or until the edges are set but the centers look slightly soft.

Cool and Serve:

Allow the cookies to cool on the baking sheet for 5 minutes before transferring them to a wire rack to cool completely.