Place Oreos and Nutella in the food processor and process until ball starts to form while the processor is running. This will take at least a minute, depending on your food processor.

If truffle mixture is too soft to roll, chill for 15 minutes. Otherwise, scoop 1 tablespoon balls of truffle dough onto a wax paper lined cookie sheet.

Chill for an additional 30 minutes.

While the truffles are chilling, melt chocolate in the microwave in 30 second spurts for about 1 1/2 -2 minutes.

once chilled dip each truffle in the chocolate. Using a spoon or fork, swirl around in the melted chocolate making sure they truffle are thoroughly coated.

Place back on the cookie sheet, sprinkle with chopped toasted hazelnuts if desired. Chill to set then store in refrigerator for up to 5 days.