-1/2 pt. ice cream. Freeze. -Serve sliced, The freezer tray of your automatic refrigerator makes wonderful cake-and-ice-cream specialties in jig time. FROZEN LADYFINGERS: Pack tray two thirds full with vanilla ice cream. Split ladyfingers, sprinkle generously with rumarrange crosswise, with flat sides down, on ice cream. Freeze. Before serving, spread generous layer whipped cream over ladyfingers. Serve sliced. BUTTERSCOTCH-ALMOND ICE-CREAM CAKE: Line bottom of tray with strips of bakers' poundcake. Spread with 1 pt. vanilla, coffee, or chocolate ice cream. Freeze. Serve sliced, with butterscotch sauce and toasted almonds. CHOCOLATE CHARLOTTE: Slice 8 spongecake layer crosswise into 1/4"-thick slices. Use to line bottom and sides of tray. Sprinkle with 2 tablesp. sherry; then spread with 1/2 pt. chocolate ice cream. Top with rest of cake, with whipped cream. Makes 6 servings. FREEZER-TRAY TRIFLE: In tray, alternate layers of spongecake strips with layers of vanilla, coffee, chocolate, butter-pecan, or strawberry ice cream, ending with cake. Sprinkle with 1/4 cup rum. Freeze. Serve sliced with crushed berries and bottled eggnog sauce or custard sauce flavored with rum.