Crush 20 Mint Oreo cookies in the food processor until they are fine crumbs.
You can crush them in a zip-top plastic bag with a rolling pin, but the creme filling tends to stick to the bag and it's hard to crush them fine enough.
Soften the 4 oz of cream cheese in the microwave about 20 seconds on HIGH. Add it to the fine cookie crumbs and pulse in the food processor just until you don't see any cream cheese. Most of the recipes I saw on used few cookie to cream cheese ratio, but it was too soft to use immediately and I didn't want to have to refrigerate the mixture first.
I find it easy and quick to use a 1 tablespoon-size cookie scoop to first scoop out the mixture onto parchment paper or wax paper. It both measures the exact amount each time and forms it into a rough ball.
The next step is simply to finish rolling them into balls. I do refrigerate the balls at this point. This is convenient for me to make the Mint Oreo Truffle Balls ahead to this point.
Then, when I have another available 30 minutes later in the day or the next day, I cover them with candy coating. Just cover them with aluminum foil or plastic wrap.
The chilled truffle balls actually makes the candy coating harden quicker. It also prevents the chocolate mixture from blending into the white coating, giving you a grey streak.
Melt white candy coating in a microwave-safe bowl at 50% power. First 1 minute, then 30 seconds at a time, stirring after each time.
Hold the truffle ball in one hand on a candy holder or a fork and spoon the melted candy coating or white chocolate with the other hand. Tap the excess coating back into the bowl.
Be sure to add the sprinkles immediately after coating each ball. The coating hardens quickly and there's no going back and adding them afterward.