Heat the oven to 350ºF. Spray an 8-inch pan with cooking spray. Prepare the sugar cookie mix according to package directions with 1 teaspoon of cinnamon added to the mixture. Press the dough evenly into the pan.Bake for 25-30 minutes or until the edges are light golden brown. Cool completely, about 1 hour.
Meanwhile, in a small bowl combine the remaining ¼ teaspoon cinnamon with 1 teaspoon sugar. Spread the vanilla frosting over the cooled bars and sprinkle with the cinnamon sugar mixture.
Recipe by Love Grows Wild at https://lovegrowswild.com/2020/12/3-easy-sugar-cookie-recipes/