Break the chocolate into small pieces, put chocolate, rum/brandy and coffee in a small heat-proof bowl and warm (in a cool oven, a microwave or over a pan of hot water) until just melted. Stir mixture well until smooth. Beat the egg yolks well, and separately beat the egg whites in a large mixing bowl until stiff. Melt the butter in a saucepan, add the combined sugar and almond meal, then add the chocolate mixture. Stir over low heat for a few minutes until all the ingredients are blended smoothly together. Off the heat, stir in the well beaten egg yolks and then fold the mixture into the stiffly beaten egg whites until well blended. Pour into a lightly buttered shallow tin* of 18 cm diameter. Cook in slow oven at 325° for 45 minutes or until cooked - test with skewer.
(*I use a 23 cm spring-form tin, cover the base with foil, then lightly grease the foil base and sides of the tin. If I am making a 2 layer cake, I line the base of two 20 cm layer tins with greaseproof paper and grease paper base and sides of the tins)