Preheat the oven to 325°F (165°C).

Add the Oreo cookies to a food processor and process until they become fine crumbs. Pour in the melted butter and pulse briefly until evenly combined.

Transfer the crumb mixture to a 9-inch tart pan with a removable bottom. Press it firmly and evenly across the base and slightly up the sides. The flat bottom of a measuring cup works well for compacting the crust.

Bake the crust for 10 minutes. Remove it from the oven and allow it to cool completely before adding the filling.

Place the chopped bittersweet chocolate in a heatproof bowl.

Heat the heavy cream in a medium saucepan over medium-high heat until very hot and small bubbles appear around the edges. Do not allow it to come to a full boil.

Pour the hot cream over the chopped chocolate. Leave it undisturbed for 4–5 minutes so the chocolate can soften.

Add the vanilla extract and gently stir until the mixture becomes completely smooth, glossy, and evenly combined.

Pour the chocolate ganache into the cooled Oreo crust. Smooth the surface with an offset spatula or the back of a spoon.

Allow the Chocolate Raspberry Tart to set at room temperature for 2–3 hours. For faster setting, refrigerate it for about 1 hour.

Arrange the fresh raspberries closely together over the chocolate filling in a circular pattern.

Lightly dust with confectioners' sugar before slicing and serving.