4 ounces dark chocolate wafer sandwich cookies (I used Quadratini brand)
1 T melted butter
4-1/2 ounces semi-sweet chocolate, chopped
1 tsp vanilla extract
Pinch of salt
2 cups heavy cream, divided
2-4 T powdered sugar (to taste)
1. Pulse the wafer cookies in a food processor until they are completely crushed and resemble wet sand. Add the butter and pulse until fully combined. Press the mixture into the bottom of an 8-inch springform pan. Chill in the fridge for at least half an hour.
2. Combine the chocolate, vanilla, and salt in a medium, heat-proof bowl.
3. Heat 6 T of the cream over medium heat until it just gets hot and begins to steam. Immediately pour over the chocolate. Wait a minute or so, and then stir until the chocolate is fully melted and the mixture is smooth. Cover and chill in the fridge for at least half an hour.
4. Pour 3/4 cup of the heavy cream into a medium bowl. Beat until stiff peaks form. Remove the chocolate mixture from the fridge and stir vigorously to loosen it up. Then add to the cream and fold together until no streaks remain.
5. Scrape the chocolate-cream mixture into the springform pan, and smooth the top. Cover and chill at least 6 hours (or up to 2 days ahead).
6. To serve, whip the remaining cream until medium peaks form. Starting with 1 tablespoon, fold in enough powdered sugar so the cream tastes lightly sweet to you. Continue beating until medium-stiff peaks form.
7. Run a knife around the edge of the pie and remove the sides, and then transfer to a serving plate. Top with the whipped cream.
8. To slice, dip a knife into hot water and dry before slicing.
9. Leftovers keep well for a day or two tightly wrapped in the fridge.