Cream the butter and sugars together until light and fluffy.
Add the egg and vanilla and mix until combined.
In a separate bowl, whisk together the flour, salt, baking soda, and cream of tartar.
Gradually add the dry ingredients to the wet ingredients and mix until just combined.
Scoop the dough into balls and roll them in the cinnamon sugar mixture.
Place the coated dough balls on a baking sheet and bake at 375°F for 10 minutes.
Allow the cookies to cool before serving.
