I stumbled across this recipe by accident several years ago and have made my chocolate cakes this way ever since - be warned - this is extremely chocolatey, fondant like texture, yummy!
200g dark chocolate
200g butter
200g caster sugar (I use half demerera/half caster)
200g ground almonds or mixed nuts
5 eggs
vanilla extract
melt chocolate & butter together, cool then add ground nuts
mix sugar and eggs (4 yolks only and 1 whole) together then add to chocolate mixture with couple drops vanilla extract
beat 4 egg whites until stiff, fold into chocolate mixture, bake on 180c for 45 mins.
Foolproof recipe & method = decadent death-by-chocolate bliss experience!