1.Preheat oven to 160°C/325°F. Grease 22cm (9-inch) baba cake pan well.
2.Beat butter and sugar in a small bowl with an electric mixer until light and fluffy. Beat in eggs, one at a time, until combined. Transfer mixture to a large bowl; stir in sifted flours and cocoa, and the water, wine and chocolate.
3.Spread mixture into pan; bake about 50 minutes. Stand cake in pan 5 minutes before turning onto a wire rack to cool.
4.Meanwhile, make red wine muscatel syrup. Stir sugar, wine and the water in a small saucepan over medium heat, without boiling, until sugar dissolves. Cut muscatels into 12 small bunches, add to syrup; bring to the per serving boil. Boil, uncovered, about 15 minutes or until syrup is reduced by one-third and is thickened slightly. Cool.
5.Top cake with muscatels, drizzle with syrup. Accompany cake with any remaining syrup, and whipped cream, if you like.