Lemon Sugar Cookie Bars are soft and chewy with lots of citrusy tang. They’re baked in a 13×9 inch dish which removes the hassle of forming individual cookies – just slice and enjoy!
Preheat oven to 350°F. Grease a 13×9-inch baking dish.
Combine the sugar and lemon zest in a medium bowl. Use your fingertips to blend the zest into the sugar until the zest is well dispersed and the sugar is fragrant with lemon.
In a separate mixing bowl, combine the flour, baking powder and salt. Whisk to combine.
In the bowl of an electric mixer, beat together butter and lemon sugar until creamy. Add the egg, sour cream, lemon juice, and extract. Beat to combine. Add the dry flour mixture and mix together on low speed until well incorporated but still crumbly. Press the mixture evenly into the bottom of the prepared pan. Bake for 15-17 minutes, or until the edges are slightly golden and the center is still pale. Cool completely before frosting.
For the frosting, cream the butter in the bowl of an electric mixer. Add about 1/3 of the confectioners’ sugar and beat until combined. Add the lemon juice and lemon zest; beat again. Mix in the remaining confectioners’ sugar, adding the milk or cream to thin the mixture to spreading consistency. Beat until light and fluffy, about 3 minutes. Add gel food color and whip until a consistent bright yellow color is achieved.
Spread the frosting evenly over the cooled cookie in the pan. Cover with sprinkles if desired. Let stand until set, about 10-15 minutes, or chill in the refrigerator until the frosting is firm. Cut into squares before serving. Store cookies in an airtight container for optimal freshness.
Keyword 13x9, american buttercream, easy christmas cookies, lemon buttercream, sugar cookies