Amish Chocolate Pie

Ingredients

1 cup sugar
2 1/2 tablespoons flour
2 tablespoons cocoa
1 1/2 cups milk
2 egg yolks
1 teaspoon vanilla
3 tablespoons butter, melted
1 9-inch baked pie crust 
Whipped cream
Chocolate Shavings

Directions

1.In a large saucepan, whisk together the sugar, flour, and cocoa.
2.In a medium bowl, whisk together the milk, yolks, and vanilla. Pour into the saucepan.
3.Turn the heat to medium and stir in the butter. Bring to a simmer and allow to thicken.
4.Pour into the baked pie crust and smooth the top. Let cool at room temperature for 2 hours and chill in the refrigerator for an additional 2 hours.
5.Top with whipped cream and chocolate shavings.