Mix the Ingredients:

In a medium-sized mixing bowl, whisk together the powdered sugar, milk (or water), corn syrup, vanilla extract, and a pinch of salt. Mix until smooth and creamy. If you prefer a thicker consistency, add more powdered sugar; for a thinner consistency, add a little more milk.

Adjust Consistency:

If you want a thicker icing for piping outlines or fine details, use less milk. For flooding the cookies with smooth coverage, add more milk to achieve a runnier texture. Adjust the consistency until it’s just right for your needs.

Add Color:

If you’d like to color the icing, divide it into separate bowls and add a few drops of food coloring to each. Mix until the color is evenly distributed. You can use gel food coloring for more vibrant hues.

Decorate the Cookies:

Once your icing is ready, you can use it to decorate your sugar cookies. Place the icing into a piping bag for more detailed designs or use a small spoon to flood the cookies with color. Let the icing dry completely, which can take about 2-3 hours, depending on the thickness of the icing.

Storage:

If you have leftover icing, store it in an airtight container at room temperature for up to a week. You can also cover it with plastic wrap, pressing it directly onto the surface to prevent it from drying out.