I have made this recipe since I was a kid. I think the original was from an old Betty Crocker cookbook. The filling is so good you can skip the pie crust and put it in pretty parfait glasses and top with whipped cream or ice cream!
Mix together the apples, brown sugar water and lemon juice in a 2-quart saucepan. Heat to boiling; reduce heat. Cover and simmer 7-8 minutes or JUST until apples are tender.
Mix together the flour, granulated sugar and salt; stir into apple mixture. Cook, stirring constantly, until mixture thickens and boils. Boil and stir 1 minute; remove from heat.
Stir in the vanilla and butter or margarine; cool.
Preheat oven to 350 degrees. Prepare pastry (or use store-bought).Turn apple mixture into pastry-lined pie plate. Cover with top crust in which you have cut slits; flute the edges. Cover edge of pie crust with foil (or cut out an aluminum pan--keeping just the edge) to prevent excessive browning; remove foil during the last 15 minutes of baking. Bake 40-45 minutes or until crust is golden brown.