Preheat oven to 180 (I currently use a fan assisted electric oven). Grease and line cake tin.

Melt 250g chocolate in a bowl over a pan of hot water. Remove from the heat and cool slightly.

Beat the butter and sugar until pale fluffy and then gradually beat in the eggs. Stir in the melted chocolate and 1 teaspoon of the vanilla essence.

Fold in the flour and almonds evenly.

Spoon mixture into tin and smooth over with spatula. Place in the oven and cook for 1 and a 1/2 hours or until risen and a skewer comes out clean.

Remove from the oven and leave to cool in the tin for 10 minutes and then turn out onto a wire rack to cool completely.

Heat the remaining chocolate and vanilla essence in a pan until melted and then blend in the Baileys. Let the mixture cool so it thickens. Cut the cake in half and spread the filling over the bottom half before sandwiching back together.