Crush the Oreos into fine crumbs with a food processor or use a Ziploc bag with a rolling pin/hammer/rock... :)
Add the crumbs to a big bowl with the softened cream cheese. I use my Kitchenaid mixer to mix until it was all well incorporated.
Roll the cream cheese Oreo mixture into 1" balls (or whatever size you'd like) Place on a cookie sheet with waxed paper. Chill in the fridge for about 1 hour.
When you truffles are almost finished chilling, start melting the chocolate slowly. (in the microwave or on the stove)
Drop one or two truffles into the melted chocolate and use a fork to remove them, letting the excess chocolate drip. Place them back on the waxed paper.
Now is when you want to add the toppings, before the chocolate hardens. I used some Christmas sprinkles I had on hand.