Sacher Torte

I have always wanted to make a Sacher Torte. Thanks to Francesca on Violet's Pantry who included this recipe in her challenge, I have now made it! This is a gorgeous rich and dense cake, surprisingly easy to make and I loved being able to ice it and pipe the obligatory "Sacher" on it, I have always wanted to do that :) (I know, I know, what a sad life I lead!)
Francesca says that this cake keeps well, which makes it a great 'make ahead' cake for a special occasion. This will be very handy to have in the arsenal for birthdays and dinner parties, impressive but easy enough to not stress about!

Sachertorte
(from Green & Black's Chocolate book)

Torte:
melted butter for greasing
200g (7oz) dark chocolate, minimum 60% cocoas solids, broken into pieces
6 eggs
310 g (11oz) granulated sugar
150g (5oz) ground almonds
1 1/2 teaspoons freshly ground coffee
6 tablespoons apricot jam

Icing:
100g (3 1/2 oz) dark chocolate, minimum 60% cocoa solids, broken into pieces
40g (1 1/2oz) unsalted butter

1. Preheat the oven to 180 C / 350 / gas mark 4. Brush the tin with the melted butter, then line it with greaseproof paper.
2. To make the torte, melt the chocolate in a heatproof bowl suspended over a saucepan of barely simmering water. Separate 5 of the eggs, then whisk the egg yolks, the whole egg and the sugar until the mixture is thick and creamy.
3. In a separate bowl whisk the egg whites until stiff peaks form.
4. Add the ground almonds, coffee grounds and melted chocolate to the egg yolk mixture and stir well. Gently fold in the egg whites and pour into the prepared tin.
5. Bake for 1 hour, covering the cake with foil after 40 minutes to prevent the top from burning. Check that a skewer inserted into the centre comes out clean and remove the cake from the oven. Release the springform and lave the cake on the base to cool on a wire rack.
6. Melt the apricot jam over a low heat, strain and then brush over the cooled cake.
7. To make the icing, melt the chocolate in a heatproof bowl suspended over a saucepan of barely simmering water. Add the butter and stir until it has the consistency of thick pouring cream. Pour the icing evenly over the cake, smoothing it over the top and sides using the back of a teaspoon. Make a pattern of rings on the top and around the sides of the cake using the back of a teaspoon. Leave to set.
8. After the icing has set use a little of the remaining icing to pipe Sacher in the traditional style