Place the chocolate and butter in a metal bowl, and place on top of a pan of simmering water until melted.
Mix the eggs and sugar in a bowl (be careful not to whisk too much).
Fold the melted chocolate into the eggs and sugar.
Lightly butter the pudding bowls, and coat the butter with a layer of sugar. Spoon in the mixture until it is 2cm from the top.
Bake in the oven at 180ºC for 10 minutes.
Serve with a scoop of vanilla ice cream.