Cup of Yum
1. Preheat the oven: Preheat your oven to 350°F (175°C). Line a baking sheet with parchment paper or a silicone baking mat.

Prepare the dough:

1. In a medium bowl, whisk together the flour, cream of tartar, baking soda, and salt. Set aside.
2. In a large bowl, cream together the softened butter and granulated sugar until light and fluffy, about 3-4 minutes.
3. Beat in the egg and vanilla extract until combined.
4. Gradually add the dry ingredients to the wet ingredients, mixing until the dough is smooth and well combined.

Prepare the cinnamon-sugar coating:

1. In a small bowl, combine the 3 tablespoons of sugar with the cinnamon.

Form the cookies:

1. Roll the dough into 1-inch balls and roll each ball in the cinnamon-sugar mixture until well coated.
2. Place the coated dough balls onto the prepared baking sheet, spacing them about 2 inches apart.

Bake the cookies:

1. Bake in the preheated oven for 10-12 minutes, or until the edges are lightly golden, but the centers are still soft.
2. Allow the cookies to cool on the baking sheet for 5 minutes before transferring them to a wire rack to cool completely.

Serve:

1. Enjoy your soft, cinnamon-sugar coated Christmas Snickerdoodles with a glass of milk or as part of a festive holiday spread!