1 cup packed light brown sugar
4 tablespoons cornstarch
1/2 teaspoon salt
2 cups milk
2 egg yolks, beaten
1 tablespoon butter
1 teaspoon vanilla extract
1 (9 inch) pie crust, baked
In top of double boiler, combine brown sugar, cornstarch, salt and milk. Cook, stirring constantly, until mixture starts to thicken, about 20 minutes.
Whisk in egg yolks; continue to cook and stir until filling is thickened.
While pudding mixture is cooking, preheat the oven to 400 degrees F (200 degrees C).
Remove filling from heat, and stir in butter and vanilla.
Pour filling into prepared pie crust. Bake in preheated oven until top begins to brown, about 5 minutes.