For the Oreo crust:
• 36 Oreo cookies, ground
• 1/2 cup unsalted butter, melted
For the hot chocolate cheesecake mousse layer:
• 1/2 cup unsalted butter, softened
• 8 ounces cream cheese, softened
• 1 cup powdered sugar
• 1 teaspoon vanilla
• 5 (0.73-ounce) envelopes of instant hot cocoa mix (milk chocolate flavor)
• 1 1/2 cups heavy whipping cream
For the chocolate pudding layer:
• 2 (3.8-ounce) chocolate instant pudding mixes
• 2 3/4 cups milk
• 1 cup mini marshmallows
For the topping:
• 1 1/4 cups heavy whipping cream (or 2 1/2 cups whipped cream)
• 2 tablespoons powdered sugar
• 2 cups mini marshmallows
• chocolate topping or Nutella for serving