Place the water, corn syrup, and 3/4 cup sugar in a saucepan and cook to 246 degrees F.
Meanwhile, whip the whites with the salt and cream of tartar in a clean dry bowl until stiff then add the 1 tablespoon sugar and continue whipping on medium speed until the syrup is ready. Drizzle in the hot syrup and then continue to mix on high for 5 minutes to cool it. Add the vanilla and water gradually to thin it out to make a sauce. Keep chilled until ready to use.
In each of 4 wide dessert bowls, place 4 slices of banana. Top them each with a small scoop of ice cream alternating flavors. Drizzle them with chocolate sauce, then alternate spoonfuls of marshmallow sauce and pineapple sauce, then sprinkle with chopped nuts.
Recipe courtesy of Gale Gand