Crust

1. Preheat the oven to 350 degrees F.
2. Put the Oreo crumbs in a bowl and pour in the melted butter. Stir until the crumbs look evenly moistened.
3. Press the mixture into a 9-inch tart pan with a removable bottom, firming up the sides and base.
4. Bake the crust for 8 to 10 minutes to set. Remove from the oven and let cool on a rack while you make the filling. Alternatively, chill the pressed crust in the fridge for at least 30 minutes.

Filling

1. Put the chopped chocolate in a heatproof bowl.
2. In a small saucepan, warm the heavy cream over medium heat until it just begins to simmer at the edges; do not let it boil.
3. Pour the hot cream over the chocolate in two pours, letting the first sit for 30 seconds. Stir gently until the chocolate melts and the mixture is glossy.
4. Add the vanilla and stir to combine.
5. Let the ganache cool about 5 minutes, then pour it into the cooled crust, tapping the pan lightly on the counter to even the surface.
6. Chill the tart in the refrigerator until the ganache is set, at least 2 hours and up to overnight.

Serving

1. When ready, arrange the raspberries on top in a single layer or loosely scattered.
2. Dust lightly with confectioners’ sugar just before serving.