Using a metal spoon, fold the chocolate mixture into the egg mixture lightly and evenly.
06Sift the flour over the top and fold in.
07Scrape the mixture into the prepared pan.
08Place in a rosting pan, transfer to the oven and pour hot water into the roasting pan to abut halfway up the sides of the cake pan.
09Bake for about 1 hour or until the cake is firm to the touch.
10Remove the cake from the water bath and place on a wire rack to cool for 10-15 minutes.
11To turn out, invert the cake onto a baking sheet, place a serving plate upside down on top, then turn plate and baking sheet over together so the cake is transferred to the plate.
12Dust with confectioners sugar and decorate with stips of pared orange zest.