DIY Creme de Menthe
from http://www.seriouseats.com/

Immortalized as the neon green ingredient in everything from cocktails to cakes, many commercial crème de menthes rely more on artificial ingredients and colorings than natural sweetness and fresh flavors. But this homemade creme de menthe tastes and smells like fresh mint. It completely blows away the commercial stuff, and it's a cinch to make and perfect for dressing up classic cocktails, like the Absinthe Suissesse and the Stinger, or mixing into your next cup of cocoa.

Notes: Since it's made with real mint, the liqueur is greenish-yellow. You can add a few drops of green food coloring if you'd like it to be greener.
It's really important that you remove all the mint leaves when straining, as any that are left will go rancid after a few days and ruin your drink!
The liqueur will keep for about 2 months. Refrigeration is not necessary, unless you'd like it chilled. Other recipes use pure mint extract instead of fresh mint leaves. If you think the flavor could be stronger, you could add a teaspoon or so of this.

1 1/2 cup fresh mint leaves, lightly packed (divided)
1 1/2 cups vodka
1 1/2 cups sugar
1 cup water

Measure out 1 cup of mint leaves and tear them in quarters or roughly chop. Place mint leaves in a sealable glass jar and pour vodka on top. Shake and let steep for 12 hours. If you let it sit much longer than that, it will actually start to develop some funky flavors. [I have seen recipes that say to steep 2 - 3 days, even 2 weeks. I would taste the ligueur at this point, and if it is not strong enough and the leaves look fairly fresh, I would steep it another day.]

After steeping is complete, strain mint leaves from infused vodka. Return infused vodka to the jar.

Bring the water and sugar to a boil, and let simmer 5 minutes. Remove from heat and let cool, then add syrup to mint-infused vodka.

Take the additional 1/2 cup of mint leaves, tear them, and add them to the jar. Shake and let steep for 10 hours.

Strain twice to remove all mint leaves, keep in resealable bottle.

Makes almost 3 cups