Ice Cold Milk

Source
Ice Cold Milk:
 * Can be looted from most level 10-23 Humanoid monsters.
 * Can be looted from Barrel of Milk.
 * Can be purchased for from various drink vendors.

Cooking

 * Bread of the Dead
 * Clam Chowder
 * Delicious Chocolate Cake
 * Winter Veil Egg Nog

As a quest objective
Ice Cold Milk is an objective for the following quests:
 * Treats for Great-father Winter
 * Treats for Greatfather Winter