Preheat the oven to 350°F. Line 2 to 3 baking sheets with parchment paper. In a medium bowl, combine the flour, cornstarch, baking soda, cinnamon, ginger, nutmeg, and salt. Set aside.
2¼ cup all-purpose flour, ½ teaspoon cornstarch, ½ teaspoon baking soda, 1 teaspoon cinnamon, 2 teaspoon ground ginger, ¼ teaspoon nutmeg, ¼ teaspoon cloves, ½ teaspoon salt
In the bowl of a standing mixer or with a hand mixer, beat the butter on medium speed until pale and fluffy, about 2 minutes. Add the brown and granulated sugar and beat on medium speed until combined and fluffy. Reduced the speed to medium-low and combine the egg and vanilla with the batter. Scrape down the sides and bottom of the bowl, add the molasses and beat until combined, about 1 minute.
1 cup unsalted butter, ¾ cup brown sugar, ⅓ cup granulated sugar, 1 large egg, 2 teaspoons vanilla extract, ¼ cup molasses
Add the dry ingredients to the bowl and beat to combine, scraping down the bowl if needed.
In a small bowl combine the sugar and spices for the spiced sugar. Scoop about 1½ to 2 tablespoons of dough, roll gently into a ball, and roll through the spiced sugar mixture and place on parchment or silpat lined baking sheets. Bake the cookies for 12 to 14 minutes. Let cool for 5 minutes on the sheet tray.
⅓ cup granulated sugar, ¼ teaspoon cinnamon, ¼ teaspoon ground ginger