Eggnog layer cake

Method

1. Heat the oven to 180°C/160°C fan/gas 4. In a large pan over a low heat, gently warm the coffee, chocolate and butter until the chocolate melts.
2. Mix the cocoa powder and sugars in a large mixing bowl, breaking up any lumps. Using a balloon whisk, gradually whisk the melted chocolate mixture into the bowl. Add the eggs, whisking until thick and smooth, then whisk in the buttermilk, vanilla extract, flour and bicarb of soda.
3. Divide the batter equally among the 3 tins and bake for 30-35 minutes or until a skewer pushed into the centre comes out clean. Leave for 5 minutes, then turn out onto a wire rack to cool.
4. Meanwhile make the filling.Heat the milk and vanilla seeds and pod in a pan until just starting to steam. In a medium heatproof bowl, using a balloon whisk, beat the sugar, cornflour and egg yolks until thick and creamy. Slowly whisk in the warm milk mixture until smooth.
5. Return the mix to the pan and put over a low heat, stirring all the time, for 10-15 minutes or until thickened. Remove from the heat and discard the vanilla pod. Pour the custard into a lipped baking tray and leave to cool.
6. Whisk the double cream to soft peaks. When the custard is cold, spoon into a large mixing bowl and beat using a balloon whisk until smooth. Gently whisk in the whipped cream, then stir in the rum/bourbon and nutmeg. Chill for at least 
15 minutes.
7. When the cakes are cool, Split the eggnog filling in half (keep the other half in the fridge until you need it) and spread it between the chocolate layers. Chill in the fridge for 15 minutes. Generously spread the remaining chilled egg nog filling all over the cake, the top and sides. Put the cake in the fridge for 60 minutes to set. Sieve a little cocoa powder or icing sugar over the top of the cake before serving. Keep the cake in the fridge to prevent the icing from becoming too gooey.