- Preheat oven to 400F.
- Mix togetherbutter, shortening and sugar in a large bowl.
- Add eggs and beat until mixture is fluffy.
- Beat in flour, cream of tartar, baking soda and salt.
- Combine 3 tablespoons sugar and cinnamon in a small bowl.
- Form dough into 1-inch balls.
- Roll balls in the sugar cinnamon mixture; place 2 inches apart on ungreased baking sheet.
- Bake 8 to 10 minutes, until cookies are lightly browned, but still soft.
Cookies will puff up at first, then flatten out.