Step 1

Preheat oven to 375 degrees F.

Step 2

Dough: Cream together butter, shortening, and 1 ½ cups sugar. Add eggs and vanilla and mix well. Add the flour, cream of tartar, baking soda and salt and stir until combined. 

Step 3

Chill dough for at least 30 minutes, if possible (or up to 3 days).

Step 4

Shape dough by heaping tablespoonfuls into balls, to make about 24 cookies.

Step 5

Cinnamon sugar: In a separate bowl, mix the 4 tablespoons granulated sugar and the cinnamon. Roll balls of dough in mixture. Place dough about 2 inches apart on a parchment lined baking sheet.

Step 6

Bake 8 to 10 minutes (don't over bake!). Allow to cool for a few minutes on the baking sheet before remove to a cooling rack to cool completely.