1.Preheat oven to 170°C (150°C fan forcedd). Grease 12-hole (⅓-cup/80ml) standard muffin pan with a pastry brush dipped in soft butter. Brush the butter quite thickly over base and up the side of each hole.
2.Chop the chocolate and the butter coarsely. Heat the chocolate, butter and the water in a small saucepan on the stove over low heat, stirring until the mixture is smooth. Pour the chocolate mixture into a medium bowl. Stir in the sugar.
3.Break the eggs, one at a time into a small cup or bowl, then pour into a medium bowl. Whisk lightly until combined, then whisk eggs into chocolate mixture.
4.Sift the flour and cocoa over the chocolate mixture, whisk until combined. Divide the chocolate mixture equally into the pan holes.
5.Cut one chocolate bar in half lengthways. Cut each half into 6 pieces. Put one cut piece of chocolate (and some of the crumbled peppermint filling that may be left after you cut the bar) into the middle of each cake.
6.Put the pan in the oven, bake the cakes for about 30 minutes. To test if cakes are cooked, insert a skewer into the centre of the middle cake. If the skewer comes out clean, the cakes are cooked. Stand the cakes in the pan for 10 minutes to allow time for the cakes to become firm enough to be carefully removed from the pan. Use a metal spatula to loosen and remove the cakes.
7.Place warm cakes on serving plates. Top cakes with a scoop of ice-cream. Chop the remaining chocolate bar coarsely and sprinkle over the ice-cream and cakes.
These are quite small cakes, so you will need to serve each person two or three. Make sure you use a good quality ice-cream.Note