01 - Whisk together powdered sugar, 2 tablespoons milk, corn syrup, and vanilla extract in a medium bowl until smooth and glossy consistency forms.
02 - If mixture is too thick, incorporate additional milk 1/2 teaspoon at a time until reaching thick but pourable texture ideal for coating.
03 - Divide icing into separate bowls for multiple colors. Gradually stir in food coloring drop by drop until achieving desired shade intensity.
04 - Apply immediately onto cooled sugar cookies using dipping method, knife spreading, or piping through bags or squeeze bottles for detailed designs.
05 - Leave decorated cookies at room temperature for minimum 4 hours or until icing surface becomes completely firm and set to touch.