Cream together butter and sugar. Add in egg and vanilla and mix until well combined.
Add flour mixture, mix well.
Press dough into the bottom of a parchment lined 8x8" baking dish.
Bake at 350F for 20 to 25 minutes, until just done. Remove from oven and allow to cool completely before frosting.
To make the frosting, mix the butter and vanilla until creamy.
Slowly add the powdered sugar while continuing to mix, then add the milk 1 tablespoon at a time.
Add a few drops of red food coloring and mix until color is evenly distributed.
Spread frosting evenly over the top of the sugar cookie, top with sprinkles.
Video
Notes
22 minutes in the oven was perfect for me. You don't want the edges to get browned because you don't want a crispy cookie bar!
Calories are automatically generated. For best results calculate based on your exact ingredients.This cookie recipe was inspired by the Publix sugar cookie recipe on the sugar bag!