Semlor - almond and whipped cream stuffed buns

For twelve buns:
50 g yeast
100 g butter
300 ml milk
75 g granulated sugar
1 teaspoon salt
500-550 g all-purpose wheat flour
For the stuffing of six buns:
100 g almond paste
75 ml milk
the crumbs from 6 buns
200 ml whipped cream

1. Melt the butter, add the milk and heat to 37 oC (100 oF), add the finely divided yeast and stir.
2. Add sugar, salt and almost all of the flour. Mix thoroughly and leave it in a warm place for 40 minutes to raise.
3. Kneed the dough and divide it into 12 parts. Form round buns, kneed them a little and leave them for 30-40 on a baking tray to raise.
4. Bake them in the oven at 225-250 oC (450 oF) for 5-10 minutes (watch carefully at the end to avoid burning the buns).
5. Cut off the top of six buns as a lid. Scoop out the crumbs and mix them with the almond paste, the milk and half of the whipped cream until you have a soft paste.
6. Fill the scooped out buns with the paste, cover with whipped cream and, finally, with the lid. If desired, sprinkle powdery sugar on top.