For the Pie Crust:

• 1 pre-made or homemade 9-inch pie crust

For the Chocolate Filling:

• 1½ cups granulated sugar
• ¼ cup unsweetened cocoa powder
• ¼ cup all-purpose flour
• ¼ tsp salt
• 4 large egg yolks
• 2 cups whole milk
• 2 tbsp unsalted butter
• 1 tsp vanilla extract

For the Meringue (Optional):

• 4 large egg whites
• ¼ cup granulated sugar
• ½ tsp vanilla extract

Instructions

1. Prepare the Pie Crust: Preheat the oven to 350°F (175°C). Roll out the pie crust and press it into a 9-inch pie dish. Bake for 10-12 minutes, or until lightly golden, and set aside to cool.
2. Make the Chocolate Filling: In a saucepan, whisk together sugar, cocoa powder, flour, and salt. In a separate bowl, whisk egg yolks and milk until smooth. Gradually add the milk mixture to the dry ingredients, whisking constantly. Cook over medium heat, stirring until thick and bubbly (7-10 minutes). Remove from heat and stir in butter and vanilla.
3. Fill the Pie Crust: Pour the chocolate filling into the baked pie crust.
4. Prepare the Meringue (Optional): Beat egg whites with an electric mixer until soft peaks form. Gradually add sugar and vanilla, beating until stiff peaks form. Spread the meringue over the warm chocolate filling, ensuring it reaches the edges of the crust.
5. Bake: Bake the pie at 350°F (175°C) for 10-12 minutes, or until the meringue is golden brown. Cool to room temperature, then refrigerate for at least 2 hours before slicing and serving.