Spray an 8×8 baking dish with nonstick cooking spray and set aside. Crush OREO cookies and set aside.
Melt 10 ounces of white chocolate chips in a microwave-safe bowl in 30 second increments, stirring in between cook times. It takes about 1-2 minutes for the chips to become completely melted and smooth.
In a microwave safe bowl, melt 10 ounces of canned vanilla frosting for 20-30 seconds. Stir the melted frosting into melted chocolate chips.
Work quickly to stir in crushed OREO cookies, sprinkles and M&Ms to the chocolate/frosting mixture. Press mixture into an even layer in the prepared 8×8 baking dish.
Allow fudge to cool in the refrigerator for about an hour in the refrigerator. Use a sharp knife to cut fudge into 1 inch squares for serving. Fudge can be stored in an airtight container for 1-2 weeks.