Combine the honey, sugars, eggs, and orange zest in a heatproof mixing bowl and whisk over a pan of simmering water until lukewarm. Grind the hazelnuts in a food processor and stir into the egg mixture. Combine all the remaining ingredients and stir in to form a soft dough.
Turn the dough out onto a floured surface and cover with a towel. Allow to rest for 5 mi