I am making brownies with baked-on toasted marshmallow/toasted coconut, and toasted marshmallow/butterscotch toppings. There also will be some chunks of dried pineapple and coconut (inside the former), and butterscotch&chocolate morsels (in the latter). Question: how and for how long can that be stored, IYO? The marshmallow topping will be out of store-bought marshmallows. Regular brownies will last a few days in air-tight container at room T, but would the marshmallow hold up for a couple of days? Also, can you freeze all that?