Combine 1/4 cup of sugar and 2 teaspoons cinnamon in a small bowl and set aside.

Cover two large baking sheet with parchment paper. Set aside.

Mix flour, baking soda, salt and cream of tartar in a mixing bowl and whisk to combine. Set aside.

Cream butter, shortening and sugars together in a large mixing bowl until smooth and creamy, with an electric mixer, about 2 minutes.

Beat in eggs and vanilla.

Slowly mix in flour mixture to combine.

Roll cookie dough into 24 balls and roll the cookie balls in the cinnamon and sugar mixture. Place cookie balls in the refrigerator for 1 hour. (I have made these without refrigerating them-they still turned out yummy! Refrigeration-optional if you are in a hurry)

Place cookie balls on prepared baking sheets and bake at 350° for 8-10 minutes. Do not over bake-ovens vary.

Remove cookies from baking sheet immediately to cool on cooling racks.

Store in an airtight contaner when completely cooled.