Lightly grease an 8-inch springform pan. Pulse the whole Oreo cookies in a food processor until they resemble fine, dark, coarse sand.

Pour the melted unsalted butter over the dark cookie crumbs. Toss with a fork until it feels like wet potting soil. Press firmly and evenly into the bottom of the prepared pan. Freeze for 15 minutes.

In a large bowl, beat the softened full-fat cream cheese, Nutella, powdered sugar, and vanilla extract until entirely uniform, glossy, and light brown. Scrape down the sides as needed.

In a separate chilled metal bowl, whip the cold heavy whipping cream on medium-high speed until sharp, stiff peaks form. Do not overbeat.

Gently fold one-third of the whipped cream into the Nutella mixture to lighten it. Then, using a sweeping under-and-over motion with a silicone spatula, fold in the remaining whipped cream until no white streaks remain.

Spoon the creamy mousse filling over the frozen dark cookie crust. Smooth the top with an offset spatula. Cover tightly with plastic wrap and refrigerate for at least 6 to 12 hours to completely solidify.

Run a hot knife around the pan's edge before releasing. Transfer to a dark stoneware plate. Use a vegetable peeler to create delicate dark chocolate shavings over the top, and garnish with fresh red strawberry halves. Serve with a silver fork.