Warm the milk in a small saucepan over low heat until it is just lukewarm, not boiling.
In a separate pan, melt the butter over low heat, then set it aside to cool slightly.
Place the dry yeast in a small bowl and add a little lukewarm water at room temperature.
Add 1 teaspoon of sugar to the yeast, stir, then cover the bowl with a small plate and leave it for about 5 minutes, until a light foam forms on top.
In a large mixing bowl add the flour, eggs, sugar, salt, melted butter, warm milk and the foamy yeast mixture.
Knead until you get a smooth, elastic dough that no longer sticks to your hands or the bowl.
Shape the dough into a ball, cover the bowl with a clean kitchen towel and let it rise for about 1 hour, until doubled in size.
For the filling, mix the farmer’s cheese with the egg, sugar and raisins until well combined. Soak the raisins in boiling water for 15 minutes, then drain them before adding.
Once risen, turn the dough onto a lightly floured surface and divide it into small pieces; with this quantity you will get around 17 pies.
Flatten each piece of dough, place a spoonful of filling in the center, then bring the sides over the filling and fold into an envelope shape.
Bring the opposite corners together over the filling so they meet in the center.
Pinch all seams firmly to seal so the filling does not leak during baking.
Arrange the pies on a baking sheet lined with parchment paper and let them rise for another 15–20 minutes.
Preheat the oven to 350°F (180°C). Beat the egg with the milk and brush the pies on top. Bake for 17–20 minutes, or until golden, adjusting the time to your oven.
The poale-n brau pies are nicely golden and puffed. Serve them warm or at room temperature.