In a large bowl, cream together the butter and sugars with an electric mixer on high speed for 2 minutes. Add the egg and vanilla and beat until smooth.
In another bowl, combine the flour, salt, baking soda, and cream of tartar.
Pour the dry ingredients into the wet ingredients and mix well.
Wrap in cling wrap and chill the dough for 60 minutes in the refrigerator. Don’t skip this step!After the dough has chilled, preheat the oven to 300-f degrees.
In a small bowl, combine the sugar with the cinnamon for the topping.
Using a 1.5 Tablespoon cookie scoop, scoop into heaping dough balls. Alternatively, take about 2 1/2 tablespoons of the dough and roll it into a ball. Roll this dough in the cinnamon/sugar mixture and place 2 inches apart on a parchment lines baking sheet. Don’t flatten the cookies.
Bake the cookies for 12 to 14 minutes and no more. Let the baked cookies sit on the hot baking sheet for 2-3 after removing from the oven, then transfer off. When the cookies have cooled they should be soft and chewy in the middle and crisp on the outside. Store in a covered container on the countertop or freeze.
