Heat oven to 400°F.

Mix 1 ½ cups sugar, the butter, shortening, and eggs in large bowl until light and creamy, about 1 minute.

Stir in flour, cream of tartar, baking soda, and salt. Mix just until the dry ingredients are incorporated, about 30 seconds.

In a small bowl, mix ¼ cup sugar and the cinnamon for the cinnamon sugar coating.

Shape dough into 1 ¼-inch balls. Roll balls in cinnamon-sugar mixture. Place 2 inches apart on ungreased cookie sheet.

Bake 8 to 10 minutes or until set. Remove from cookie sheet to wire rack to cool.