After you are finished making the various sundae components, scoop ice cream into a very large oval dish or platter. Place a scoop of the pineapple and strawberry sauces on top of the ice cream with a dollop of the cocoa whipped cream. Drizzle on the butterscotch and chocolate syrups then stick 2 banana bonbons into the bowl.
Trim the pineapple and slice into long quarters. Cut the flesh from the skin and slice each quarter in 3, lengthwise. Chop into little pieces, taking care to catch the juice. Combine the pineapple juice and rum and whisk in the cornstarch, creating a slurry. In a saucepan, melt the butter and brown sugar to bubbling. Add the pineapple and bring to a boil. Add the slurry and cook until bubbling and the cornstarch cannot be tasted.
Slice the strawberries, and macerate half of them in the sugar and Grand Marnier until juicy. Before serving, stir in the remaining strawberries.
Using whisk or electric beater, beat cream until almost thickened. Add cocoa powder and confectioners' sugar and continue beating until the ingredients are blended in and the whipped cream is firm.
Combine the water, sugar, and butter in a large saucepan and cook over high heat until light amber, about 5 minutes. Stand back as far as possible and slowly drizzle the cream into the pan. It will bubble up and may splatter, so protect your hands with an oven mitt or towel. Add the rum and cook for 4 to 5 minutes, occasionally swirling the sauce around the pan, until thickened and a rich golden brown. Strain the sauce and stir in the sweetened condensed milk. Store in a sealed container. This sauce will keep for 2 weeks in the refrigerator or 3 months in the freezer.
Finely chop the chocolate and put in a medium bowl. In a small saucepan, heat the coffee and corn syrup to a simmer. Pour the mixture over the chocolate and gently stir with a whisk until smooth and blended. Store in a sealed container. This syrup will keep for 4 weeks in the refrigerator or 6 months in the freezer.
Melt chocolate in a completely dry bowl or in the top of a double boiler set over barely simmering water. Pierce each of the banana chunks with 2 toothpicks. Dunk first into the chocolate to coat, then into the peanuts or coconut. Set on waxed paper-lined cookie sheet and freeze for 2 hours or overnight. For maximum flavor, let sit at room temperature for 10 minutes before serving.
Sub-Recipes courtesy Wayne Harley Brachman and Retro Desserts, by Wayne Harley Brachman, Harper Collins Publishers, 2000