Using a medium size mixing bowl, stir together the powdered sugar, corn syrup, clear vanilla, almond extract and milk. Stir until no lumps are visible.
Evenly divide the icing between 4 small bowls. Add 3 - 5 drops of the desired gel food color to the icing.
Gel food color
When you are ready to decorate your cookies, pour the icing into individual quart size ziploc bags or piping bags. Allow the iced cookies to sit for 12 - 24 hours to fully set and harden.
Video
Notes
Tips:
I only use gel food coloring, because liquid coloring adds extra liquid that thins the icing and keeps it from setting properly.
I start with the smaller amount of milk. If the icing gets too runny, I stir in a little more powdered sugar, and if it's too thick, I add milk a few drops at a time.
I decorate cookies only once they're completely cool, and I add sprinkles right away while the icing is still wet so they stick.
I let the iced cookies dry uncovered for 12 to 24 hours before stacking or packing them, even if the tops look dry sooner.
Squeeze bottles work in place of the bags, and they're easier for kids to handle. The recipe doubles easily.
Storage:
Keep leftover icing in an airtight container or in the bags in the refrigerator for up to 3 days, and bring it to room temperature before using. Freeze leftover icing for up to 1 month and thaw it in the refrigerator overnight. Once the icing is fully dry, store decorated cookies in an airtight container at room temperature for up to 1 week with parchment paper between the layers, or freeze them for up to 1 month. The icing loses some of its shine in the freezer.