Preheat the oven to 350°F (175°C).

Line a baking sheet with parchment paper.

In a large mixing bowl, beat the softened butter and granulated sugar together until light and fluffy.

Mix in the eggs one at a time until fully incorporated.

In a separate bowl, whisk together the flour, cream of tartar, baking soda, and salt.

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

In a small bowl, combine the granulated sugar and ground cinnamon for rolling.

Using a cookie scoop or spoon, portion out the dough and roll it into balls.

Roll each ball in the cinnamon-sugar mixture before placing them on the prepared baking sheet.

Bake for 8-10 minutes until slightly golden around the edges but still soft in the center.

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