1 cup (2 sticks) unsalted butter
2 cups plus 2 tablespoons all-purpose flour (see Cook's Note)
1 teaspoon baking soda
1 teaspoon cream of tartar
1/4 teaspoon fine salt
1 cup plus 2 tablespoons granulated sugar
1/4 cup packed light brown sugar
1 large egg
2 teaspoons ground cinnamon
When measuring flour, we spoon it into a dry measuring cup and level off the excess. (Scooping directly from the bag compacts the flour, resulting in dry baked goods.)