New Zealand Billy Sponge

This is from "Jo Seagar's New Zealand Country Cookbook". The author says that it used to be cooked in a billy in a camp oven or coal range. She said it makes a nice dessert with fresh or poached fruit and ice cream or whipped cream. Also great with bacon, bananas and maple syrup for brunch or breakfast. I guess what makes this one is the cracked sugar coating and the "rather chewy texture". I have not made this, but I want to do so. I don't think I would use Pam spray for this because I'm not sure it would create the crackly sugar coating she talks about. I'd use butter. ETA: One reviewer said that a family member really liked this with lemon sauce.