I've been using this recipe for so long that I don't remember where it came from. I do remember that I'm asked to bake 3 pies every Thanksgiving. Two are for the dinner and the third one is for my sister's partner who demands a whole pie for himself.
PIE: In a large bowl, combine lemon juice and apples; toss until well coated. Stir in sugar, flour, cinnamon, and 1/8 t. salt; mix well. Turn into a 9 inch unbaked pie shell. Cover edges of the pie shell with aluminum foil. Bake for 20 minutes.
TOPPING: Melt morsels and butter over hot (not boiling)water or in microwave; stir until smooth. Remove from heat; stir in flour and remaining 1/8 t. salt. Blend until mixture forms large crumbs. Remove foil from pie. Crumble mixture over top of hot apples. Bake for another 25 minutes.
I serve while still slightly warm with whipped cream or ala mode.