For the crepes: Put the milk, chocolate and butter in a saucepan and heat to melt. Beat the eggs with the sugar in a bowl. Add the vanilla, then the flour. Beat in the chocolate mixture. Strain into a jug and let sit for 30 minutes. Add more milk or water if necessary to give the consistency of thin cream. Fry the crepes in a nonstick pan. If you do not have a nonstick pan use a bit of oil.
For the chocolate sauce: Put the chocolate and cream together in a saucepan and heat, gently, until the chocolate has melted and the mixture is very smooth. Thin, as needed with more cream. Serve hot.
To serve: Fill the crepes with sliced banana or strawberries and sweetened cinnamon-flecked whipped cream. They look best folded over into a triangle. Drizzle chocolate sauce over top.