PREHEAT oven to 350º F. Grease 13 x 9-inch baking pan.
CUT pineapple slices in half for a total of 20 half rings; set aside. Microwave 2/3 cup morsels, water, 1 tablespoon butter and corn syrup in small, uncovered microwave-safe bowl on MEDIUM-HIGH ( 70%) power for 30 seconds; STIR. If morsels retain some of their original shape, microwave at additional 10- to 15-second increments, stirring until smooth. Immediately pour and spread mixture into prepared pan. Arrange halved pineapple slices on top of mixture in three rows of 7, 6 and 7. Sprinkle almond slices in between pineapple slices.
MICROWAVE remaining1 cup morsels in small, uncovered microwave-safe bowl on MEDIUM-HIGH (70 %) power for 45 seconds; STIR. If morsels retain some of their original shape, microwave at additional 10- to 15-seconds increments, stirring until smooth.
COMBINE flour, baking powder, salt and nutmeg in small bowl. Beat 6 tablespoons butter and sugar in large mixer bowl until creamy. Add eggs, one at a time, beating well after each addition. Add melted morsels and vanilla extract; mix well. Gradually beat in half of flour mixture. Gradually beat in milk and remaining flour mixture. Spread batter evenly over pineapple layer.
BAKE for 30 to 35 minutes or until toothpick inserted in center comes out clean. (If necessary, loosely cover cake with a piece of aluminum foil for the last 10 minutes of baking, as top of cake may darken.) Remove from oven to wire rack. Cool for 5 minutes. Poke holes in cake and brush reserved 2 tablespoons of pineapple juice all over cake surface.
RUN thin knife around the edges of the pan. Place serving platter over the pan. While keeping firm grip on both, flip pan over and place platter, cake and pan on rack. Let pan sit on top of cake for 5 minutes. Remove pan and replace any pineapple pieces stuck to pan. Brush top of cake with rum, if desired. Serve warm or at room temperature.
1/4 to 1/2 teaspoon rum extract mixed with 2 tablespoons of water can be used instead of rum or scotch.