Ingredients:

• 1 (9-inch) pie crust, baked
• 1 1/2 cups sugar
• 1/2 cup unsweetened cocoa powder
• 3 tablespoons cornstarch
• 1/4 teaspoon salt
• 3 cups milk
• 3 egg yolks
• 2 tablespoons butter
• 1 1/2 teaspoons vanilla extract
• Whipped cream for topping