Preheat your oven to 325°F (165°C) and line an 8x8-inch pan with parchment paper.

Combine crushed chocolate sandwich cookie crumbs and melted salted butter in a mixing bowl, then press into the bottom of the pan. Bake for 8 minutes and cool.

Fill a rimmed baking dish with about 1 inch of water and place it in the oven for a water bath.

Beat softened cream cheese until smooth, then add granulated sugar, sour cream, and vanilla extract, mixing until creamy.

Separate half the filling and fold in Nutella into one half, and crushed Oreo into the other half.

Layer the batters into the cooled crust, swirling Nutella on top for a marbled effect.

Bake for 55-65 minutes until edges are set. Cool completely at room temperature, then chill for at least 2 hours.