For the colorful jam buns, 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 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 50 g liquid butter, add dampfl and remaining flour and knead with dough hooks until smooth. Cover and let rest again for about 20 minutes.
Form a roll from the yeast dough on a floured work surface, divide it into approx. 15-20 equally sized pieces (large or smaller Buchteln, as desired). Form a small ball from each piece and flatten slightly. Fill each with a teaspoon of jam and seal. Dip into the remaining melted butter.
Place in a prepared ovenproof dish and let rest, covered again, for 20 minutes. Bake in a preheated oven at 180 °C for about 20-25 minutes until golden brown. Let the colored jam cakes cool down and serve them sprinkled with powdered sugar.
Preparation Tip:
Colorful jam cakes are best served with vanilla sauce.