Cake:

1. Fill a roasting tin with water; place in bottom of oven as it heats.

2. Grease and line a 10"x2" round cake tin.

3. Break chocolate into pieces; melt in a heatproof bowl over simmering water.

4. Cut butter into small cubes; add to chocolate.

5. Allow butter to melt into chocolate; remove from water and allow to cool for 15 minutes.

6. Preheat oven to 350 F.

7. In a clean bowl, whisk egg yolks and sugar together until thick, pale, and creamy.

8. In another bowl, whisk egg whites until stiff but not dry.

9. Stir melted chocolate mixture into egg yolk mixture.

10. Add rum and vanilla extract.

11. Sieve in flour; add egg whites.

12. Carefully fold ingredients together until well mixed; do not beat too much air out of mixture.

13. Transfer to prepared cake tin; smooth top.

14. Bake in center of oven for 50-55 minutes or until just firm to touch.

15. Allow to cool in tin on a wire rack for 30 minutes; remove from tin and cool completely on rack.

16. Frost with Glossy Chocolate Cream, below.

Glossy Chocolate Cream:

1. Melt chocolate in a heatproof bowl over simmering water.

2. Remove from water; set aside to cool until slightly warm, about 30 minutes.

3. While whisking the chocolate, gradually pour in cream; whisk until thickly whipped and glossy.

4. Spread immediately; will harden once chilled.