Preheat the oven to 200° C. Warm the milk until lukewarm, about 37 degrees.
In a separate large bowl, mix the the fresh yeast and 100 grams of sugar until incorporated.
Pour the milk into the yeast and sugar mixture while stirring. Mix and let it sit for about 30 seconds.
Add the all-purpose flour and salt, and then the softened butter, kneading well. It starts off as a rather shaggy and sticky dough but knead until the dough becomes smooth and does not stick to your hands and the bowl anymore. If needed, add more flour.
Let the dough rise in a warm place under a towel until doubled, for about an hour*.
To make the filling, mix the necessary ingredients until smooth.
Once the dough has risen, form it into small balls (about 60 - 65 grams)** and place on a baking tray covered with parchment paper. Let the the dough balls prove under a towel for about 15 minutes.
After proving, using the bottom of a round glass, press a well in the dough balls that will hold the filling. The well should be quite deep. Brush the edges with the beaten egg mixture. Fill the wells with the curd cheese mixture. Use around 2 - 3 tablespoons of filling per pastry.
Bake at 200° C for about 15 - 18 minutes or until golden brown on the sides.
Let them cool slightly before diving right into them. If you wish, lightly sprinkle some powdered sugar on them. Enjoy!