Old-Fashioned Chocolate Pie

In a bowl, whisk together the sugar, flour, and cocoa powder.
Gradually add the dry mixture to the melted butter, stirring to prevent any lumps.
Add Milk:
Slowly add the milk to the saucepan while stirring until the mixture is smooth.
Cook Until Thickened:
Cook the mixture for 5-7 minutes, stirring constantly, until it thickens. Once thickened, remove from heat.
Temper Egg Yolks:
In a separate bowl, whisk the egg yolks. Add a spoonful of the hot chocolate mixture to the yolks to temper them, then gradually stir the yolks back into the saucepan.
Finish Cooking:
Return the saucepan to the heat and cook for 2-3 minutes, stirring constantly. Stir in the vanilla extract and remove from heat.
Assemble the Pie:
Pour the chocolate filling into the pre-baked pie crust and spread evenly.
Prepare Meringue: