For the butter croissants, mix all dry ingredients. Dissolve the yeast in the milk. Knead all ingredients well. Let the dough rest for about 1/4 hour.
Grind the dough pieces into round balls of about 80 g each. Cover and let rise for about 20 minutes. Flatten dough balls by hand and roll out oval approx. 12×18 cm.
Roll in with both hands with a slight outward movement so that you can see the pattern well. Shape into croissants and place on a baking sheet.
Cover and let rise for about 1/2 hour. Beat the egg with a little milk and brush the croissants with it. Heat the oven to 195 °C using a fireproof container.
Add water to the hot container to create enough steam. Bake for approx. 15 minutes until golden.