Step 1: Prepare the Pie Crust
• Pre-bake Crust: If using a homemade crust, preheat the oven to 350°F (175°C). Mix the graham cracker crumbs with melted butter and press into a pie dish. Bake for 8-10 minutes, then let cool. If using a pre-made crust, skip this step.

Step 2: Make the Chocolate Filling
• Heat Cream: In a saucepan over medium heat, heat the heavy cream until it begins to simmer. Remove from heat and add the chocolate chips, stirring until melted and smooth.
• Mix Egg Yolks: In a separate bowl, whisk together the egg yolks, sugar, cornstarch, and milk until smooth.
• Combine: Gradually add the chocolate mixture to the egg yolk mixture, stirring constantly to prevent curdling. Return the mixture to the saucepan and cook over low heat, stirring until thickened (about 5 minutes).
• Add Vanilla: Remove from heat and stir in the vanilla extract. Let the filling cool slightly.

Step 3: Assemble the Pie
• Fill Crust: Pour the chocolate filling into the prepared pie crust, smoothing the top with a spatula.
• Chill: Cover with plastic wrap and refrigerate for at least 2 hours, or until set.

Step 4: Add Cherry Topping
• Top with Cherries: Once the chocolate filling is set, spread the cherry pie filling evenly over the top of the chocolate layer.
• Garnish: If desired, garnish with fresh cherries and whipped cream before serving.