Blend 1 cup milk, sweetened condensed milk, Oreos, cocoa and cornstarch until smooth.

In 3 quart saucepan over medium/low. heat remaining 3 cups milk until just barely steaming. (8-10 minutes) Whisking occasionally.

Add chocolate Oreo mixture and continue to heat while whisking for 5-10 more minutes. Do not allow mixture to boil.

Remove from heat. Serve topped with whipped cream and Oreo Cookie crumbles.