A festive Holiday Milkshake: Oreo Peppermint Milkshake.  You only need 5 ingredients to make this delicious treat. This milkshake is bursting with winter flavors.   "Peppermint extract is an herbal extract of peppermint (Mentha x piperita) made from the essential oils of peppermint leaves. It is commonly used in cooking as a dietary supplement, and as an herbal or