Melt 4 cups miniature marshmallows with 1 cup milk over medium heat, stirring constantly. Chill until cool, slightly thickened. Beat 1 cup whipping cream. Fold cream into cooled marshmallow mixture. Turn 1/2 into pan covering crumb mixture. Top with 1 can pie filling. Cover with remaining cream mixture. Sprinkle with reserved crumbs. Chill at least 6 hours.