How to make
Dissolve the yeast in a bowl with about 4/5 cup (180 ml) of warm water and add sugar. Allow it to activate, add salt and pour into the well of the sifted flour. Add milk and knead the dough until it becomes soft and smooth. Form a ball and leave it in a bowl, cover with a damp cloth and let it rise for 2 hours at room temperature.
Then, knead it again, pressing with your fist. Roll it out in a rectangle and distribute the butter in the center. Fold the sheet in three. Gently roll out with a rolling pin and fold again - first one end toward the middle, then the second on top. Leave in the fridge for 30 minutes.
You can repeat the entire procedure with the addition of more butter, folding and placing in the fridge, or you can do it only once. Finally, roll it out into a rectangle, cut it into squares and then the squares into triangles. Wrap them into croissants, brush them with beaten egg and leave them to stand for about 1 hour.
Preheat the oven to 430°F (220 °C), smear the croissants again with beaten egg and put them to bake for about 15-20 minutes. Optionally, you can then fill them with cream, chocolate or jam.