Toppings you can use other than crushed cookies include crushed pistachio nuts, hazelnuts or walnuts. You can also use jam, marmalade or seasonal fresh berries.
Sweetened condensed milk lasts refrigerated for about three weeks. It can also be frozen so any excess milk can be used for other portions of this dessert or in a Vietnamese coffee. ( Just stir a teaspoon of sweetened condensed milk in a cupful of freshly percolated coffee ).