For classic Dukatenbuchteln with amaretto vanilla sauce, first dissolve yeast in half of the lukewarm milk and mix with a little flour to form a mushy dough. Cover with a little flour and let it rise in a warm place (approx. 35 °C) for 20 minutes (= steam).
Mix the remaining milk, egg, yolk, salt, granulated sugar, rum, lemon zest and 60 g liquid butter, add the Dampfl and the remaining flour and knead with the dough hooks to a smooth dough. Cover and let rest again for about 20 minutes.
Form a roll from the yeast dough on a floured work surface, divide it into about 30 equal-sized pieces. Form a small ball from each piece and dip into the remaining melted butter. Place in a prepared ovenproof dish, cover and let rest for another 20 minutes. Bake in a preheated oven at 180 °C for about 20-25 minutes until golden brown.
Bring the milk and cream to the boil with the sugar and the sliced vanilla pod, mix the yolks with cornstarch and a little water and stir into the milk. Bring to the boil once, remove the vanilla pod and refine the sauce with Amaretto.
Serve classic ducat buns with amaretto-vanilla sauce.