Place one pie shell in 9-inch pie plate. Pour apples and their juice into the shell. Sprinkle with the lemon juice.
Combine sugar, flour and cinnamon and distribute evenly over apples. Place butter pats randomly over apple filling. Top with second piecrust. Bake in 350-degree oven for about 45 minutes, or until pie is golden.
About 5 or 10 minutes before pie is done, melt 1 tablespoon butter. Off the heat, whisk in vanilla and heavy cream and sift in the powdered sugar until mixture reaches thickness of cream gravy. As soon as pie is removed from oven, slather with the sugar icing. Mark off 8 servings with the pecan halves.