Sacher torte batter
Preheat the oven to 180 ºC / 355 ºF. Butter a 20 cm cake tin. Bring all your ingredients out of the fridge, because it's very important that they're at room temperature. Make the Sacher torte batter. Melt the chocolate in a bowl, over a saucepan of boiling water. When the chocolate has melted, remove it from the heat and let it cool slightly. In a large bowl, beat the butter with the icing sugar for about 3 minutes, using an electric mixer. Add the cooled, melted chocolate and mix for another 3 minutes. Add the egg yolks one by one and beat to incorporate.
In another clean bowl, beat the egg whites and a pinch of salt with caster sugar into soft peaks, using an electric mixer. Incorporate the sifted flour with the butter - sugar - chocolate mixture, using a spatula. Make sure there are no lumps of flour in the better. Mix 1/3 of the egg whites with the flour-butter-sugar-chocolate mixture. Then gently fold in the rest of the egg whites, using a spatula.TipIt's really important to fold the egg whites gently into the batter to assure a soft inside of Sacher torte.
Pour the batter into the prepared cake tin and bake the cake for 40 - 45 minutes at 175 ºC / 350 ºF. Transfer the baked Sacher torte to a wire rack to cool.
Spread a layer of jelly
Put the apricot jelly to a saucepan and bring to a boil, remove from the heat. Cut the baked cake on half and spread a thin layer of apricot jelly over the half, than cover with another half and spread a thin layer of apricot jelly over and around the rest of the cake.
Chocolate glaze and serve
Make the glaze. Place the water and caster sugar in a saucepan and bring to a temperature of 108 ºC / 225 ºF. Lower the heat, add the chocolate and stir constantly until it melts. Pour the glaze over the cake immediately. Set the cake aside to cool for at least 30 minutes. Serve with Chantilly cream.