Melt the fat in a saucepan, add the milk and warm up lukewarm. Crumble yeast into it and dissolve it while stirring. Mix flour, 50 g sugar and salt in a bowl. Add 1 egg. Add yeast milk and knead with the dough hooks of the hand mixer to a smooth dough.
Cover and leave to rise in a warm place for about 1 hour.
Grease a spring plate (top 30 cm Ø, bottom 28 cm Ø) and dust with flour. Roll out approx. 1/3 yeast dough on a floured work surface to a circle (approx. 28 cm Ø). Carefully lift into the mould.
Form the remaining dough into a roll and cut into approx. 16 slices. Put approx. 1 tsp. marzipan on each slice, seal the dough around it and form it into cakes. Distribute the pastry to the inner edge of the tin.
Let it go again in a warm place for about 45 minutes.
Pour cherries in a sieve. Mix quark, 2 eggs, 75 g sugar and 1 pinch of salt with a whisk. Add pudding powder and mix thoroughly. Pour the quark mixture into the Buchtelring and gently swirl the cherries.
Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: see manufacturer) on the bottom rack for approx. 45 minutes.
Remove the cake from the oven, place on a cake rack and allow to cool. Remove from the tin, stir icing sugar and 2 tablespoons of water until smooth and spread it streakily over the cakes.