Start this recipe by making the chocolate brandy mousse. Melt the chocolate and the butter together in a pan over boiling water, and remove from heat. In a bowl, whip the double cream to soft peaks and put to one side. In a second bowl, whisk the eggs with the honey together until light and fluffy. Fold in the orange zest and brandy, followed by the melted chocolate mixture and then the whipped cream. You should have a rich, glossy chocolate brandy mousse. Pour the mousse into 4 tall glasses and refrigerate for at least 1 hour. Meanwhile, make the sesame caramel by putting the water and caster sugar together in a saucepan. Turn on the heat, and leave to bubble for about 5 minutes, till you have lightly golden caramel. Add in the sesame seeds, mix well and continue to cook till the caramel until it has turned a darker shade of golden brown. When ready, immediately pour the sesame caramel onto an oiled piece of greaseproof paper and flatten with a palette knife. (Do not touch the hot caramel with your fingers as it will burn). Once the sesame caramel is evenly flattened out, leave it to cool and harden for 20 minutes. When you are ready to serve, remove the chilled chocolate brandy cups from the fridge. Break up the hardened sesame caramel and place 2 pieces on the top of each glass.