Preheat oven to 350°F.

In a large bowl, mix flour, cream of tartar, baking soda, and salt. Set aside.

In a stand mixer, cream together butter (barely softened) and sugar. Add eggs and vanilla and blend well.

Add dry ingredients to wet ingredients and mix well.

In a small bowl, combine ⅓ cup sugar and 2 tablespoons cinnamon.

Use a small cookie scoop to scoop out dough and roll it into a ball. Roll each ball in the cinnamon sugar mixture – twice.

Place 2 inches apart on an ungreased cookie sheet.

Bake for 8-10 minutes. Let sit on the cookie sheet for a few additional minutes before removing to a wire rack to cool.