Butterscotch Pie

In heavy saucepan mix sugar, flour, egg yolks and salt; slowly add all milk and use a wire whisk or wooden spoon to combine.

Cook over medium heat until it starts to thicken, add butter and cook until thick and creamy.

Remove from heat and add vanilla.

Pour into baked pie shell and top with egg whites which have been beaten until they hold soft peaks beating in 1/4 cup sugar.

Spread over filling and bake until brown at 375°.