In a large mixing bowl, combine your butter and cream cheese until well mixed and fluffy. Add in vanilla and peppermint extract (if using).
Add in a few drops of green food coloring until the desired hue is reached. Remember that your color will lighten when you add in powdered sugar.
Add in salt (optional) and powdered sugar about 1/2 cup at a time, until you reach your desired consistency. 3 1/2 cups might be enough for some, depending on your butter and cream cheese, while some may need the entire 4 cups (or even a tad more). You want a very thick frosting - much thicker than what you'd frost a cake with, but still able to stir.
Add in your chocolate chips.
If needed add in a drop or two more food coloring. Stir until well combined.
Place mixture in refrigerator for at least two hours.
Once chilled use a small scoop to create scoops of ice cream and place onto mini cones. Depending on the size of your scoop (I made mine about 1-1 1/2" in diameter) you should get about 24 cones. Place in the fridge while you prepare your chocolate.
Prepare your chocolate coating according to package directions. Make sure it's not too hot.
Drizzle a small amount of chocolate on top of frosting scoops if desired to mimic hot fudge. Add sprinkles or toppings and allow to dry.
Store in refrigerator.