1. Make the dough: Cut the Kerrygold Unsalted Butter in four 1 tablespoon-size pieces and place in the bowl of an electric stand mixer fitted with the dough hook attachment. Add the flour, sugar, salt, and yeast. Turn the mixer on medium low speed to gently combine the ingredients for 1 minute. With the mixer on low, slowly pour in the milk. Once all of the milk is added, turn the mixer up to medium speed and mix the dough for at least 5 minutes. The dough will be soft. It will pull away from the sides of the bowl, and the dough should be springy. If the dough is still sticking to the sides, run the mixer for another 2-3 minutes.
2. With floured hands, remove the dough from the bowl, and shape it into a ball. Place the dough on a parchment paper lined baking sheet, or lightly floured baking sheet. Gently flatten the dough out, and cover with plastic wrap or a clean kitchen towel. Place the entire baking sheet in the refrigerator and allow the covered dough to rest in the refrigerator for 30 minutes.
3. Remove the dough from the refrigerator. It shouldn’t be too cold at this point, and will feel like clay. Use your hands to start to flatten the dough out. Roll it out into a 14×10-inch rectangle, be as precise as possible with the measurement, while shaping it into the rectangular shape.
4. Place the rolled out dough back onto the baking sheet, parchment paper and all. Cover the rolled out dough with the plastic wrap or towel, and place the entire baking sheet in the refrigerator and allow the covered dough to rest in the refrigerator for 4 hours or overnight.
5. Butter layer (start this 35 minutes before the next step so the butter can chill for 30 minutes): In a stand mixer fitted with a paddle attachment, beat the butter and flour together until smooth. Transfer the mixture to a parchment lined baking sheet. Use a spoon or small spatula to smooth it out into a 7×10-inch rectangle. Place the entire baking sheet in the refrigerator and chill the butter layer, uncovered, for 30 minutes. The butter layer should be firm but still pliable.
6. Laminate the dough: Remove both the dough and butter layers from the refrigerator. Place the butter layer in the center of the dough and fold each end of the dough over it. If the butter wasn’t an exact 7×10-inch rectangle, use a pizza wheel or sharp knife to straighten out the edges. Seal the dough edges over the butter layer as best you can with your fingers. On a lightly floured counter, roll the dough into a 10×20-inch rectangle, with the shorter edge of the dough facing you. If the dough starts to be oval shaped, keep working it with your hands and rolling pin until you have the correct size rectangle. Fold the dough lengthwise into thirds as if you were folding a letter. This is the 1st turn. You want to keep the dough cool, so if it is now too warm to work with, and starts to become sticky, place the folded dough on the baking sheet, cover with plastic wrap or aluminum foil, and refrigerate for 30 minutes before the 2nd turn.
7. 2nd turn: Turn the dough so the short end is facing you. Roll the dough out once again into a 10×20-inch rectangle, then fold the dough lengthwise into thirds as if you were folding a letter. The dough must be refrigerated between the 2nd and 3rd turn, since it has been worked a lot. Place the folded dough on the baking sheet, cover with plastic wrap or a clean kitchen towel, and refrigerate for 30 minutes before the 3rd turn.
8. 3rd turn: Roll the dough out once again into a 10×20-inch rectangle. Fold the dough lengthwise into thirds as if you were folding a letter.
9. Long rest: Place the folded dough on the lined baking sheet, cover with plastic wrap and refrigerate for 4 hours or overnight.
10. Shape the croissants: Remove the dough from the refrigerator. On a lightly floured counter, roll the dough out into an 8×20-inch rectangle. Use your fingers if you need to stretch the dough into a rectangular shape. Use a sharp knife or pizza wheel to slice the dough in half vertically. Each skinny rectangle will be 4 inches wide. Then cut 3 even slices horizontally, giving you 8 4×5-inch rectangles. Cut each rectangle in half lengthwise so you have 16 2×5-inch rectangles. Work with one rectangle at a time. Gently roll or stretch the dough out about 8 inches long. Place a few small pieces of chocolate in a single layer at one end of the rectangle, tightly roll the dough up around the chocolate for one roll, then add another piece of chocolate, and tightly roll all the way up. Make sure the seam side is down. Repeat with the remaining dough, placing the shaped croissants on 2 parchment lined baking sheets, 8 per sheet. Loosely cover with plastic wrap or aluminum foil and allow to rest at room temperature for 1 hour, then place in the refrigerator to rest for 1 hour or up to 12 hours.
11. Preheat the oven to 375° F. Whisk the egg well for the egg wash. Remove the croissants from the refrigerator. Brush each lightly with egg wash. Bake the croissants: Bake until croissants are golden brown, about 30 minutes. Rotate the pans halfway through baking. Remove the croissants from the oven and place on a wire rack to cool for a few minutes before serving. Optional: dust with confectioners’ sugar before serving.
Recipe by Lion’s Bread.