Mile-High Chocolate Pie

INGREDIENTS

• 1 pie crust, homemade or store-bought
• 4 large egg whites
• 3/4 cup plus 3 tablespoons sugar
• 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
• 1/2 cup crème fraîche
• 1/8 teaspoon kosher salt
• A 9" pie dish