Prepare the Oreo Crust

• Preheat your oven to 350°F (175°C).
• Crush the Oreo cookies into fine crumbs using a food processor.
• Mix in the melted butter until the mixture resembles wet sand.
• Press the crust mixture evenly into the bottom and sides of a 9-inch pie dish.
• Bake for 8–10 minutes. Let the crust cool completely before adding the layers.

Make the Flourless Chocolate Cake Layer

• Melt the bittersweet chocolate and butter in a medium saucepan over low heat, stirring until smooth.
• Remove from heat and whisk in the water, cocoa powder, salt, and vanilla extract.
• In a large bowl, beat the egg yolks with half the granulated sugar until pale and fluffy.
• In another bowl, beat the egg whites until soft peaks form, then gradually add the remaining sugar and beat until stiff peaks form.
• Gently fold the chocolate mixture into the egg yolks.
• Gradually fold the whipped egg whites into the batter, being careful not to deflate it.
• Pour the batter over the cooled Oreo crust and bake for 15–18 minutes, or until set. Cool completely.

Prepare the Chocolate Pudding Layer

• In a medium saucepan, whisk together the granulated sugar, cocoa powder, cornstarch, and salt.
• Gradually add the egg yolks and milk, whisking until smooth.
• Cook over medium heat, stirring constantly, until the mixture thickens and begins to simmer (about 5–7 minutes).
• Remove from heat and stir in the butter, chopped bittersweet chocolate, and vanilla extract until smooth.
• Let the pudding cool slightly, then pour it over the flourless chocolate cake layer. Smooth the top and refrigerate for at least 2 hours until set.

Make the Whipped Cream Topping

• In a large mixing bowl, whip the heavy cream and granulated sugar together using a hand mixer until soft peaks form.

Assemble the Pie

• Spread the whipped cream evenly over the chilled chocolate pudding layer.
• Garnish with cocoa powder, chocolate curls, or crushed Oreos if desired.

Serve and Store

• Slice the pie and serve chilled.
• Store leftovers in an airtight container in the refrigerator for up to 3 days.