Preheat oven to 325°F. Line a 9 x 13-inch dish with foil.

Pulse Oreo cookies, cream included, in a food processor until crumbs. Mix together crumbs and melted butter. Press evenly into bottom of prepared pan.

Bake crust for 11 minutes. Remove and cool.

Place a large sheet pan on the bottom oven rack and fill half full of water. Let oven preheat to 325°F again.

Beat cream cheese and sugar until creamy. Add sour cream and flour and beat again.

Add eggs and beat just until mixed in. Remove 1 cup of batter and set aside.

Pour melted white chocolate and Crème de Menthe into the big bowl of cheesecake batter. Beat until mixed together. Pour on crust.

Add melted chocolate to reserved batter and beat until mixed in. Use a spoon to drop chocolate batter on top of cheesecake batter in the pan.

Use a butter knife to swirl gently. Do not go all the way to the bottom.

Place the pan of cheesecake on the oven rack above the steaming water. Bake for 50–55 minutes or until the sides are set and the center is still slightly wiggly. Remove and place on a wire rack to cool for an hour, then refrigerate until chilled through.

Place a metal bowl and beaters in the freezer for 10 minutes. Pour in heavy cream and powdered sugar. Beat until stiff peaks form.

Spoon into a piping bag fitted with icing tip 1M. Swirl on cheesecake bars and top with sprinkles, if desired.