Preheat oven to 400 degrees F.

Cream together butter & shortening. Add in 1 1/2 cups sugar and beat for a few minutes until light and fluffy, then add eggs, beating after each.

In another bowl, mix flour, cream of tartar, soda and salt. Add to the butter mix and stir in on low-speed, using a spatula to scrape up dough from the bottom.

Shape dough by rounded spoonfuls into balls about 1 1/4″ in diameter. See note.

Mix the 1/4 cup sugar and the cinnamon in a shallow container. Roll balls of dough in mixture. Place 2 inches apart on ungreased baking sheets.

Bake 8 to 10 minutes, or until the edges are set but the center of the cookie is puffed and still a little jiggly. Remove immediately from baking sheets.

Note: A scoop helps here and if you’d like, just drop by the scoopful into the cinnamon sugar until you have 10 or so, then pick them up, roll them into a round shape, roll them in the sugar, place them on the tray and repeat.

Note: a one teaspoon scoop works well for these cookies.