Heat oven to 400ºF
Mix 1 1/2 cups sugar, the butter, shortening and eggs in large bowl.
Stir in flour, cream of tartar, baking soda and sea salt.
Shape dough into 1 1/4-inch balls. Mix 1/4 cup sugar and the cinnamon.
Roll balls in cinnamon-sugar mixture. Place 2 inches apart on un-greased cookie sheet.
Bake 8 to 10 minutes or until set.
Remove from cookie sheet to wire rack for cooling down.