Step 1: Prepare the Dough

1. In a small bowl, dissolve the yeast in warm milk and let it sit for 5–10 minutes until foamy.
2. In a large mixing bowl, combine flour, sugar, and salt.
3. Add the yeast mixture, melted butter, and egg. Mix until a dough forms.
4. Knead the dough on a lightly floured surface for about 8 minutes until smooth and elastic.
5. Place the dough in a greased bowl, cover it, and let it rise for about 1.5 hours or until doubled in size.

Step 2: Laminate the Dough

6. Roll out the dough into a large rectangle (about 12×18 inches).
7. Spread the softened butter evenly over two-thirds of the dough.
8. Fold the unbuttered third over the middle third, then fold the remaining third on top (like folding a letter).
9. Turn the dough 90 degrees and roll it out again into a large rectangle. Repeat the folding process twice more.
10. Wrap the dough in plastic wrap and refrigerate for at least 1 hour.

Step 3: Shape the Gipfeli

11. Roll out the dough into a ¼-inch thick rectangle. Cut into triangles (about 4 inches wide at the base).
12. Starting from the base, roll each triangle tightly towards the tip, forming a crescent shape.
13. Place the Gipfeli on a baking sheet lined with parchment paper. Cover and let them rise for 30–45 minutes.

Step 4: Bake the Gipfeli

14. Preheat the oven to 375°F (190°C).
15. In a small bowl, mix the egg yolk and milk. Brush the Gipfeli with the egg wash.
16. Bake for 18–22 minutes, or until golden brown and flaky.
17. Let them cool slightly before serving.