Add the whole Oreos (cream and all) to a food processor and pulse to fine crumbs. Reserve a couple of tablespoons of crushed cookies for decorating if you like. Add the cream cheese in chunks and pulse again until well combined and dough-like.*
Roll the mixture into 1-inch balls with the palms of your hands and place on a wax paper-lined baking sheet. Transfer to the freezer for 15-30 minutes.
In the meantime, melt the chocolate in a microwave-safe bowl. Start with 30 seconds, stir, and continue in 15-second increments, stirring vigorously after each one. When the chocolate is mostly melted, with a few unmelted pieces remaining, stop heating and stir until all the chocolate is melted. Be careful not to overheat.
Dip the truffles in the melted chocolate, rolling them around gently with a fork until completely coated. Pick the truffle up with the fork and tap the fork on the edge of the bowl to let the excess drip off. Transfer back to the lined baking sheet. If you are adding sprinkles or crushed cookies, add them now before the chocolate sets.
Transfer the baking sheet to the refrigerator to let the chocolate firm up.