In a stand mixer, combine 4 cups of all-purpose flour, 1/4 cup of granulated sugar, 1 tsp of salt, and 2 1/4 tsp of instant yeast. Gradually pour in 1 1/4 cups of cold whole milk while kneading with a dough hook for about 5 minutes, until the dough is soft yet slightly tacky. Cover the dough with plastic wrap and refrigerate for 30 minutes to allow it to rest and firm up.

While the dough rests, prepare the butter layer by beating 1 cup of softened unsalted butter with 2 tbsp of all-purpose flour until smooth. Shape the mixture into a rectangle, wrapping it in parchment paper. Refrigerate for 30 minutes until firm but still pliable, which is essential for creating those glorious flaky layers.

Roll out the chilled dough on a floured surface into a large rectangle. Place the butter layer in the center and fold the dough over to encase the butter completely. Seal the edges securely, then roll the dough into a rectangle again. Fold it into thirds like a letter, wrap it in plastic, and refrigerate for 30 minutes. Repeat this process two more times.

After completing the lamination process, refrigerate the folded dough for 4 hours or overnight. This solidifies the layers and makes the dough easier to shape.

Once chilled, roll out the dough on a floured surface into a large rectangle, about 1/4-inch thick. Cut the rectangle into smaller triangles. Place a chocolate baton at the wide end of each triangle, then roll the dough tightly towards the pointed end. Arrange them on a baking sheet lined with parchment paper and proof for 1 hour at room temperature, followed by another hour in the refrigerator.

Preheat your oven to 400°F (204°C) while the croissants finish their final rise. Brush the tops of each croissant with an egg wash made from 1 large beaten egg and 1 tbsp of milk. Bake for approximately 20 minutes, rotating the pans halfway through for even browning.