This is a completely fine swap for marshmallows. Just know that the bread with turn into a crouton, and that you'll want to use an unflavored slice (i.e. don't use garlic or onion bread). Others swear ...
Mix the glaze ingredients together and pour over the layer of fat. Score the fat into diamond shapes and roast for about 20-25 minutes, or until golden-brown, basting halfway through the cooking time.
If you want to reduce the added sugar in your cakes it can be difficult to know where to start. Many sugar substitutes are expensive and cutting out sugar can ruin a bake. Happily there are some ...