01 -
In a medium bowl, whisk together the confectioners' sugar, milk, corn syrup and extract (if using). Add more milk as necessary to achieve a honey-like consistency that drizzles easily off a spoon while remaining thick. Cover the bowl with plastic wrap or a damp towel if not using immediately.
02 -
Use a toothpick, small skewer or chopstick to swirl a small amount of the food coloring through the icing, leaving visible streaks. Avoid overmixing to preserve the tie-dye appearance. Multiple colors can be used, but be mindful that excessive mixing will muddy the final result.
03 -
Working one at a time, carefully dip each cookie face down into the glaze. Turn the cookie right side up and transfer to a cooling rack, allowing excess glaze to drip off. If the colored streaks diminish during dipping, add more food coloring and re-swirl as needed.
04 -
Allow the icing to set completely for at least 4 hours (and up to 12). Store finished cookies in an airtight container at room temperature for up to a week.