The recipes for both the peanut brittle and the marshmallow cream make more than you will need for the ice cream. Making either in smaller amounts would be difficult. You will use about half the peanut brittle in the ice cream and maybe ⅓ of the marshmallow cream. Store the cream in the freezer for a few weeks so you can use it in more ice cream or to top tarts. The Sicilian Gelato base is based loosely on this recipe from Ice Cream Nation. The recipe for marshmallow cream is based on this one from Chow.com. That recipe is measured in volume, and I haven't converted it yet, so volume it is.