For the chocolate nut cake, cream warm butter with half the honey, vanilla sugar, orange zest and gradually the egg yolks.
Beat egg whites to snow and finish beating with remaining honey. Pull the snow into the drift. Mix hazelnuts, flour and chocolate well and loosely incorporate together with milk.
Line a pan with baking parchment, pour in the mixture and bake at 170°C for about an hour. Turn out the chocolate-nut cake and remove the paper.