Chocolate Cinnamon Cookies

CHOCOLATE CINNAMON COOKIES 1 1/4 cups all-purpose flour1/4 cup unsweetened cocoa powder1 tsp ground cinnamon1 1/2 teaspoons cream of tartar1/2 teaspoon baking soda1/4 teaspoon salt10 tablespoons unsalted butter (at room temperature)3/4 cup granulated sugar1/4 cup...