In a large mixing bowl, combine 1 cup of softened butter with 1.5 cups of sugar. Beat on medium speed for 3-4 minutes until light and fluffy.

With the mixture still mixing, add 2 room temperature eggs one at a time, allowing the mixture to blend fully after each addition.

In a separate bowl, whisk together 2.75 cups of sifted all-purpose flour, 2 tsp of cream of tartar, 1 tsp of baking soda, and 0.5 tsp of salt.

Gradually fold the dry ingredient mixture into the creamy butter and egg mixture using a spatula until just combined.

Cover the bowl with plastic wrap and refrigerate the dough for at least 1 hour, or up to overnight.

In a shallow bowl, mix together 3 tbsp of sugar and 2 tsp of ground cinnamon for the coating.

Preheat your oven to 350°F. Roll the chilled dough into 1-inch balls and coat each in the cinnamon-sugar mixture.

Place the balls onto parchment-lined baking sheets with at least 2 inches of space between them. Bake for 9-11 minutes until edges are golden.

Let the cookies cool on the baking sheets for 2-3 minutes before transferring to a wire rack to cool completely.