I have Marcel Desaulniers Death By Chocolate book that has directions for one. Even has French fries and ketchup if I remember correctly. It's too long to type out but I'm sure we can figure out a way to get it to you if nobody has a link for one.
Oops, it's the Burger Meister book. Buns are cake, burger is chocolate mousse, cheese is white chocolate and pickles are sliced kiwis. Fries are folded, cinnamon sugared pastry dough and ketchup is a rasberry-OJ relish