Cornetto Italian Butter Croissant

In a large bowl, dissolve the yeast and a pinch of sugar in the warm milk. Let it sit for 5-10 minutes until foamy. Add the remaining sugar, flour, salt, whole egg, and vanilla extract (if using). Mix until a shaggy dough forms, then turn it out onto a lightly floured surface. Knead for about 7-10 minutes until smooth and elastic. Place the dough in a lightly oiled bowl, cover, and let it rise in a warm place for 1 to 1.5 hours, or until doubled in size.

Once risen, gently punch down the dough and shape it into a rectangle. Wrap it tightly in plastic wrap and refrigerate for at least 30 minutes. While the dough chills, arrange the cold butter slices between two sheets of parchment paper and roll it into a thin rectangle, roughly 20x25cm. Ensure the butter remains cold and pliable. Return the butter rectangle to the refrigerator until needed.

On a lightly floured surface, roll out the chilled dough into a rectangle about twice the size of your butter slab. Place the cold butter slab onto one half of the dough, leaving a small border. Fold the other half of the dough over the butter, sealing the edges firmly to enclose the butter. Gently roll the dough out again into a long rectangle, about 25x60cm. Fold the dough into thirds, like a business letter. Wrap it in plastic wrap and refrigerate for 30 minutes.

Repeat the rolling and folding process two more times. Each time, remove the dough from the fridge, rotate it 90 degrees, roll it out, fold it into thirds, wrap it, and refrigerate for 30 minutes. This precise technique builds the characteristic flaky layers of the cornetto. After the third turn, refrigerate the dough for at least 1 hour, or preferably overnight, to allow the gluten to relax completely.

Remove the dough from the refrigerator and roll it out on a lightly floured surface into a large rectangle, about 3-4mm thick. Trim the edges to create a neat rectangle. Cut the dough into long triangles with a base of about 8-10cm and a height of approximately 20-25cm. Starting from the wide base, gently roll each triangle towards the tip, forming the cornetto shape. Curve the ends slightly to create the classic crescent.

Place the shaped cornetti on a baking sheet lined with parchment paper, ensuring ample space between them. Cover loosely with plastic wrap and let them proof in a warm place for 1.5-2 hours, or until visibly puffy and almost doubled in size. Preheat your oven to 190C (375F). Whisk the egg yolk with 1 tablespoon of melted butter for an egg wash and brush it gently over the cornetti. Bake for 15-20 minutes, or until golden brown and beautifully flaky. Let them cool slightly on a wire rack before serving.