In a large trifle bowl (or other clear glass bowl), put the strawberries, bananas, biscotti, cake, and whipped cream in random layers. Drizzle the dulce de leche and chocolate sauce between layers, saving a generous portion of each for the top. Scoop out and serve in individual bowls.
*To make dulce de leche: Put a can of sweetened condensed milk in a pot and cover with water. Bring the water to a simmer and cook for 3 hours, turning the can over every half hour and topping off with more hot water if it evaporates. Turn off the heat and leave the can in the water until it is completely cool.