To make the compote, peel and core the apples and cut into chunks. Place in a large pot with the apple juice and heat. Simmer, covered, about 20 minutes or until the apples are chunky and soft. Taste and add sugar as needed. (You want this to be tart.)
Add 2 tablespoons of cassis preserves per cup of applesauce. Adjust the cassis to the sweetness of the apples.
To make the meringue shells, beat the egg whites with a dash of salt on the high speed of an electric mixer just until soft peaks form. Gradually beat in the sugar, 1/4 cup at a time, beating well after each addition. Beat in the lemon juice and vanilla. Continue beating 12 minutes longer. The meringue batter should be very thick.
With an ice cream scoop or a large spoon, drop mounds of the meringue on a greased cookie sheet, keeping each ball smooth. Make a deep pocket in the center of each by twirling the back of a teaspoon around.
Bake in a preheated 200-degree oven for 1 hour. Turn the oven off and leave the meringues for another half hour. Cool and fill them with about 1/2 cup compote per meringue.