Sugar Cookie Bars

Sugar Cookie Bars Yields - 36 bars --Bars-- 1 cup butter, softened 3/4 cup granulated sugar 3/4 cup, brown sugar 3 large eggs 1 large egg yolk 1 tablespoon vanilla extract 3 cups all-purpose flour 1 teaspoon salt 2 teaspoons baking powder 3 teaspoons cornstarch 1 1/2 cups rainbow sprinkles, divided --Frosting-- 3/4 cups butter, softened 2 cups confectioner sugar 1 teaspoons vanilla extract 1/2 - 1 teaspoon salt 3-5 tablespoons, whipping cream Food coloring, as desired --Bars-- Preheat oven to 350 Line a 9x13 pan with parchment paper, set aside In the bowl of a stand mixer cream together butter and sugars until light and fluffy Add in eggs, yolk & vanilla mixing until just combined, scraping down the sides as necessary In a medium bowl whisk together flour, salt, baking powder, cornstarch and 1 cups of the sprinkles Slowly add in flour mixture to butter mixture, until just combined, making sure to not over mix Press batter into prepared pan Bake for 24-26 minutes or until top and edges are lightly browned and center is set Remove from oven & let cool in the pan completely --Frosting-- In the bowl of a stand mixer, or large bowl, whip butter until light Slowly add in confectioners sugar, mixing until smooth, scraping down the sides as needed Add in vanilla & salt, mixing until just combined Add in cream, 1 tablespoon at a time, until desired consistency is reached (I used 3) Add 1 drop of food coloring (if using) at a time until desired color is reached Frost cookie bars and top with remaining sprinkles Cut and ENJOY!!