In a medium bowl, whisk together flour, salt, baking soda, cream of tartar and ground cinnamon. In a large bowl, using a mixer beat softened butter with granulated sugar until fluffy.
Add in eggs and vanilla extract and beat until smooth. Add in the flour mixture in three additions, beating after each until fully incorporated. Cover and refrigerate dough for at least one hour.
Preheat oven to 350 F. In a small bowl, combine sugar and cinnamon. Roll cookie dough into balls and roll into the cinnamon sugar mixture. Place cookie dough 2-inches apart onto ungreased baking sheets. Bake for 10-12 minutes.
