Oreo Crust

1. Crush the Oreo cookies into fine crumbs using a food processor.
2. Mix with the melted butter until evenly combined.
3. Press the mixture firmly into the bottom and sides of a 9-inch (23 cm) pie dish.
4. Refrigerate for at least 30 minutes while preparing the chocolate mousse.

Chocolate Mousse Filling

1. Whisk the eggs and sugar in a heatproof bowl over a saucepan of gently simmering water, stirring constantly. Use a thermometer to monitor the temperature.
2. Remove from the heat and stir in the melted chocolate, vanilla extract, and salt. Let cool until lukewarm.
3. Beat the softened butter in a stand mixer fitted with the whisk attachment for about 5 minutes, until pale and creamy.
4. Add the chocolate mixture gradually, mixing until smooth and fully combined.
5. Whip the cold heavy cream in a separate bowl until firm peaks form.
6. Fold the whipped cream gently into the chocolate mixture using a spatula until smooth and airy.
7. Spread the chocolate mousse filling evenly over the chilled Oreo crust.
8. Refrigerate for at least 4 hours, preferably overnight, until completely set.

Chocolate Curls

1. Chill a baking sheet in the freezer for about 10 minutes.
2. Melt the chopped chocolate in the microwave or over a double boiler.
3. Spread a thin layer of melted chocolate over the cold baking sheet using an offset spatula.
4. Scrape the chocolate with a metal spatula once it has set but is still slightly flexible, forming chocolate curls. Keep in a cool place.

Whipped Cream Topping

1. Combine the cold heavy cream, powdered sugar, and vanilla extract in a mixing bowl.
2. Whip until medium-stiff peaks form, being careful not to overwhip.
3. Spread the whipped cream over the chilled chocolate pie.
4. Decorate with chocolate curls and refrigerate until ready to serve.