
Use a Teflon coated cake mold. If you do not have a Teflon mold, you can line a regular cake mold with foil which has been buttered. Make sure that the foil rises about the pan as the cake will increase 20% in volume while baking.
Break the chocolate into pieces and put into a double boiler. Make a half cup of coffee or espresso and add to the chocolate along with the cognac. Cut the butter in cubes and put it together with the chocolate. Melt the chocolate over low heat until smooth and creamy.
Beat the eggs in a bowl while gradually adding flour. Make sure there are no lumps.
Great orange peel and add half to the chocolate mixture. Be sure to only grate the orange portion and not the white pith.
Add the warm chocolate to the well-beaten eggs and mix until smooth and even. Fill the mold and sprinkle the remaining orange zest over the top. Bake at 350 degrees for 35 minutes.
Let cake cool 45 minutes before serving. Cut thin slices. May be served with whipped cream or custard.