10 ounces semisweet or bittersweet chocolate (do not exceed 71% cacao), chopped, plus more shaved with a vegetable peeler for garnish
3 tablespoons unsalted butter
4 cups heavy cream, divided
1 cup coarsely crushed chocolate wafer cookies (such as Nabisco Famous Chocolate Wafers), divided
½ cup crème fraîche
? teaspoon kosher salt
A 9" pie dish
YIELD Makes 10 servings
Step 1 :
Preheat oven to 350°F.
Line pie dish with crust; crimp edges decoratively.
Fully bake pie crust according to recipe or box instructions.
Let cool completely.
Step 2 :
Whisk egg whites and sugar in a medium heatproof bowl set over a medium saucepan of simmering water until sugar dissolves and egg whites are warm but not hot, 3-4 minutes.
Remove from heat.
Using an electric mixer, beat on medium-high speed until cool, tripled in volume, and stiff peaks form (the tips of the peaks won't fall over when beaters are lifted from bowl and turned upright), about 6 minutes.
Step 3 :
Stir chopped chocolate and butter in a large bowl set over same saucepan of simmering water until melted and smooth, 4-5 minutes; set aside.
Step 4 :
Beat 2 cups cream in another medium bowl until medium peaks form (cream should be soft and pillowy), 5-6 minutes.
Step 5 :
Gently fold egg whites into warm chocolate mixture until fully incorporated (work quickly to prevent chocolate from turning gritty).
Gently fold in whipped cream just until no white streaks remain; do not overmix or mixture will deflate.
Spoon ½ cup chocolate mousse into bottom of prepared pie crust; spread evenly over bottom of crust.
Sprinkle ¾ cup plus 2 tablespoons crushed chocolate wafers over mousse.
Top with remaining mousse, mounding in the center to create a dome. (The point is to add height, not to spread out evenly to edges.)
Step 6 :
Beat remaining 2 cups cream, crème fraîche, and salt until medium-stiff peaks form (when the beaters are lifted from the cream, the peaks will hold their shape but the tips will fall over).
Top chocolate mousse with whipped-cream mixture, following the same rounded dome shape.
Chill pie for at least 4 hours or, covered, for up to 3 days. (It will slice best if chilled overnight, allowing mousse to set properly.)
Step 7 :
Garnish pie with 2 tablespoons chocolate wafers and chocolate shavings.
Slice pie using a clean, dry knife; wipe between slices to ensure clean, elegant pieces.