I cannot remember if I posted this last year, but if so, the recipe is worth repeating. I tripled it, which was a bit much for the mixer, so next time I would double and then make a separate single batch.
2 1/4cups (11 1/4 ounces) unbleached all-purpose flour
2teaspoons cream of tartar
1teaspoon baking soda
1/2teaspoon salt
12tablespoons (1 1/2 sticks) unsalted butter , softened but still cool
1/4cup vegetable shortening
1 1/2cups (10 1/2 ounces) granulated sugar , plus 3 tablespoons for rolling dough
2 large eggs
1tablespoon ground cinnamon for rolling dough
INSTRUCTIONS
1. Adjust the oven racks to the upper- and lower-middle positions and heat the oven to 400 degrees. Line 2 large baking sheets with parchment paper or spray them with nonstick cooking spray.
2. Whisk the flour, cream of tartar, baking soda, and salt together in a medium bowl; set aside.
3. Either by hand or with an electric mixer, cream the butter, shortening, and the 1½ cups sugar at medium speed until combined, 1 to 1½ minutes. Scrape down the sides of the bowl with a rubber spatula. Add the eggs. Beat until combined, about 30 seconds.
4. Add the dry ingredients and beat at low speed until just combined, about 20 seconds.
5. Mix the 3 tablespoons sugar for rolling and the cinnamon in a shallow bowl. Working with a heaping tablespoon of dough each time, roll the dough into 1½-inch balls. Roll the balls in the cinnamon sugar and place them on the prepared baking sheets, spacing them about 2 inches apart. Note: When shaping the first ball, make sure that the dough is not too soft (so that it is melting in your hands.) If it is, refrigerate it for 15 minutes and then proceed.
6. Bake until the edges of the cookies are beginning to set and the centers are soft and puffy, 9 to 11 minutes, rotating the baking sheets front to back and top to bottom halfway through the baking time. Let the cookies cool on the baking sheets 2 to 3 minutes before transferring them with a wide metal spatula to a wire rack.