Preheat the oven to 350ºF.
Combine the cookie crumbs and melted butter in a medium-size mixing bowl. Thoroughly mix together, then press into the bottom of a 10-inch springform pan.
Beat the cream cheese in a food processor until smooth. Add the sugar and process. Add the eggs 1 at a time, running the processor in between each addition. Add the heavy cream, flour, salt, and vanilla and process until smooth, scraping down the sides of the bowl as needed. With the motor running, add the chocolate in a steady stream. Pour the mixture into the prepared pan. Bake until the center of the cake sets, about 1 hour and 15 minutes.
Remove from the oven and loosen the sides of the cake with a thin knife. Cool completely. If you like it slightly chilled, refrigerate for about 1 hour.
In a medium-size mixing bowl, combine the Grand Marnier and berries, cover, and refrigerate for at least 2 hours.
To serve, slice the cheesecake, spoon the berries on the slices, and top with the whipped cream and mint sprigs.
Yield: one 10-inch cheesecake; 12 servings