Place the ice cream, milk, mint extract, and green food coloring in a blender. Puree until smooth.
Divide between two glasses, top with whipped cream and enjoy!
Green color: If you want a darker shade of green, you’ll need a few more drops of food coloring. You can also try a gel food color, which is more concentrated. You typically only need 2-3 drops of food gel for every 10 drops of food coloring.
Mint extract: Plain mint extract uses spearmint, which is much milder than peppermint. Peppermint extract contains significantly more menthol, which gives it a more intense flavor. Traditional shamrock shakes use plain mint extract, but either will work. Just keep in mind that if you use peppermint extract, you will get a stronger punch of mint flavor.
Adjusting consistency: Play around with the ratio of ice cream to milk to make your shake exactly how thick you like it. Add more ice cream if it needs to be thicker or more milk to thin it out.
Adding alcohol: Feel free to make this a spiked milkshake! Crème de menthe would be a great substitute for the mint extract, but you may need to double or triple the amount to get that strong minty flavor. You could also experiment with mint and whipped cream vodkas if you’d like.
Vegan and dairy-free versions: Oat or soy milk make great substitutes for the milk; if you use coconut milk, be sure to go for the full-fat canned version. If you use rice milk, use less since it is thinner. Oat and soy based ice creams will also work well; if you use coconut milk ice cream, the milkshake may have a grainier texture.
Different flavors of ice cream: You could totally experiment with different ice cream flavors. Regular chocolate, mint chocolate chip, or even pistachio might be good ones to try.