Cup of Yum
1. In a large bowl, mix the yeast with the warm milk, add the sugar and 1 cup of flour. Mix until smooth. Lightly flour the surface, cover and let stand for 30 minutes in a warm, draft-free place.
2. Melt the butter and let it cool.
3. In the bowl of a stand-mixer, pour the egg and egg yolks and beat them lightly. Add the vanilla, zest of lemon, warm melted butter, and mix.
4. Add the yeast and flour mixture. Start kneading and gradually add the remaining flour.
5. Knead for 3 minutes at medium speed, then stir in the salt.
6. Knead again for 3 minutes.
7. Cover the bowl and let the dough rise for 30 minutes (at about 85F/30C, away from drafts).
8. Mix the powidl and the rum.
9. Preheat the convection oven to 350F/185C.
10. Place the dough on a lightly floured work surface and gently punch it down.
11. Divide dough into 15 pieces of about 2 oz (60g) each.
12. For a circle with each piece of dough, then drop a teaspoon of powidl in the center and fold the sides to enclose the powidl. Form a ball.
13. Turn each ball over and place them in a buttered rectangular pan.
14. Place all the balls of dough next to each other and brush them generously with melted butter.
15. Let the buns rise again for 20 minutes at room temperature, away from drafts and brush them with butter again.
16. Bake for 25 to 30 minutes.
17. As soon as they are out of the oven, brush the buns with butter again, and let them cool on a rack.
18. Sprinkle with icing sugar.

Sauce

1. Split the vanilla pod lengthwise, scrape the seeds and mix them with the milk in a saucepan.
2. Put the pods into the milk and bring it to a boil.
3. Take the saucepan off the heat and infuse for 20 minutes.
4. In a bowl, beat the egg yolks and the sugar.
5. Return the milk to the heat and bring back to boil.
6. Remove the vanilla pod from the milk and, while beating the egg yolks, gradually pour the boiling milk.
7. Put the mixture back in the saucepan on medium to low heat, stirring constantly, until thickened.
8. Cool quickly by placing the pan in water and ice to stop the cooking and add the cream, while stirring constantly.
9. Serve hot or warm buchty with the vanilla cream.