In a mixing bowl (with a stand mixer preferred), add white chocolate morsels and marshmallow crème. Set aside.

In a large saucepan melt butter with sugar, heavy cream and salt. Cook and stir over medium high heat until mixture begins to boil.

Continue stirring and boil for 5 full minutes. Remove from heat. Pour mixture into bowl over the white chocolate and marshmallow.

Beat with whisk for 1-2 minutes until white chocolate has melted and mixture is smooth. Fold in crushed oreos.

Pour fudge into a 9-inch square baking dish lined with parchment paper. Refrigerate 4 hours or overnight.

Remove from baking dish with parchment paper. Trim off edges (if you want perfect squares) then cut fudge into 1inch bite sized pieces.

Store in an airtight container in the refrigerator for up to two weeks.