Preheat oven to the maximum, fan assisted.
Whip the egg whites for about 5 minutes until they are firm, then add the sugar and whip until you get a glossy and thick meringue.
Fold in thoroughly the honey, the vanilla essence and the egg yolks, then fold gently in the flour sifted with the baking powder. Mix in the hazelnuts and the white chocolate.
Line with parchment paper a large baking pan and with the help of a spoon form two loaves of dough keeping them well separated, about 5 cm wide and 30 cm long.
Reduce the oven temperature to 180°C, then bake the cookies for about 20 minutes, then remove them from the oven, let cool for 5 minutes and then cut them slantwise into 2 cm thick slices with a sharp knife, then arrange them cut-side-down in the baking tin and put them back in the oven for about 5 - 10 minutes, until toasted.
You can store them in a tin for several days.