2 9-inch pie crusts, softened
FOR THE FILLING:
10 oz bittersweet chocolate, plus more for topping
1 1/3 cups granulated sugar
2 teaspoons vanilla extract
1/2 cup (1 stick) unsalted butter, softened
2 1/2 cups heavy whipping cream
1/3 cup powdered sugar
Preheat oven to 350°F and grease a half sheet pan with nonstick spray. Set aside.
On a lightly floured surface, stack pie crusts on top of each other and roll out into a rectangle that’s slightly larger than your baking pan. Place crust in pan, pressing into the corners, cut off excess dough, and crimp.
Line crust with parchment paper and fill with pie weights or dried beans. Bake until slightly golden, about 15-17 minutes. Remove from oven and let cool completely before filling.
In a microwave-safe container, melt the chocolate in 30-second increments, stirring in between, until nearly melted. Then, stir until completely melted. Set aside.
In a medium saucepan, whisk sugar and eggs together. Reduce heat to low, and stirring constantly, heat until sugar has dissolved and mixture coats the back of a spoon, about 5 minutes.
Remove from heat and stir in the melted chocolate and vanilla extract until smooth. Let cool until warm, stirring occasionally.
While chocolate cools, add butter to a mixing bowl and beat until light and fluffy, 2-3 minutes. Gradually pour in the chocolate mixture, then beat on high until light and fluffy, about 5 minutes. Set aside.
In a separate bowl, beat the heavy cream with an electric mixer until it starts to thicken. Add powdered sugar and continue beating until stiff peaks form.
Fold 1 1/2 cups of the whipped cream into the chocolate mixture and reserve the rest for topping.
Spread chocolate mixture into cooled pie crust and chill until set, 1-2 hours. Top with remaining whipped cream and garnish with chocolate shavings, if desired, before serving.