Cut heart shapes from the sugar cookie dough and bake them according to the recipe or package directions. Allow the cookies to thoroughly cool.
Prepare the cookie icing by sifting the powdered sugar into a small mixing bowl and then stirring in the milk. Add the corn syrup and stir until the mixture is smooth.
Use the toothpick to poke a small hole in the corner of the plastic bag. Then spoon a third of the icing into the bag. Set the bag aside for now.
Stir drops of red food coloring into the remaining icing in the bowl until you have the desired shade.
Cover your working surface with a sheet of waxed paper. Working with one cookie at a time, spread the tops with the colored icing and immediately use the icing-filled plastic bag to pipe on white dots. (If you do this while the tinted frosting is still fluid, the dots will spread nicely to the same level.) To keep the dots as round as possible, lift the bag straight up from the cookie after you've piped the icing. You can practice the technique beforehand by piping a few dots onto a piece of waxed paper.
Article provided by Spoonful.com