Orange-Filled Donuts

1. In a small bowl, dissolve the yeast in 1/2 cup of lukewarm water.
2. Add 2 tbsp of flour and mix until you obtain a batter.
3. Cover with a towel, then let it rest for about half an hour - until the batter rises to twice its original size.
4. In a large bowl, mix the rest of the flour with the sugar, a pinch of salt, egg, egg yolks, and whipped butter.
5. Mixi well until smooth.
6. Add the yeast-flour mixture and mix / knead well using your hands.
7. Form a ball of dough, then cover with a towel and let it rise (leave for about 2 hours).
8. Use a rolling pin to roll the dough flat - about 4 mm thick.
9. Cut the dough into discs - about 3 inches diameter.
10. Place a tablespoon of the jam or marmalade on the surface of the disc, then cover with another disc.
11. Press the sides well to seal in the filling.
12. Repeat for the rest of the donuts.
13. After this, let it rest for about 20 minutes.
14. Deep-fry the donuts in hot oil until golden brown.
15. Do not cook more than 2 donuts at a time.
16. Top with powdered sugar.
17. Serve warm or chilled.