Take two half-sheet-sized pieces of parchment paper and place one on top of the other. I usually keep these parchment sheets on hand to make it easy.

Use a ruler and pen to mark two lines 8" (20cm) apart, equidistant from each outer edge.

Use the ruler to draw 12" (30cm) lines through the marks on each side.

Connect the 12-inch lines at the top and bottom to create an 8x12" (20x30cm) rectangle.

Fold both parchment papers tightly along the marked lines.

Flip the folded papers so the folds are at the bottom.

Place the softened butter between the parchment papers and press it into a flat layer.

Flatten the butter evenly using the side of a rolling pin, pushing it into each corner.

Place a small sheet tray or something wide and flat on top of the parchment paper to make the butter evenly flat.

Transfer the butter block to a half sheet tray to keep it flat, then to the refrigerator and let it firm up.

In the bowl of a stand mixer, combine warm water, yeast, sugar, salt, flour, and scalded milk.

*To scald the milk, heat to 180 then cool in the fridge for about 10 minutes or until the temp is around 90F

Attach the dough hook to the stand mixer and mix on low speed for 2-3 minutes, or until the dough comes together.

Increase the speed to high (this is a 4/10 on my KitchenAid) and add the softened butter gradually, one piece at a time.

Continue mixing on high speed for 5 more minutes until the dough develops gluten and clears the sides of the bowl.

Check the dough by performing the tug test to ensure it is elastic and doesn't tear.

Transfer the dough to a bowl and shape it into a tight ball by rounding and tucking it up under itself.

Cover the bowl with a lid and let the dough ferment at room temperature for 90 minutes or until it doubles in size.

Remove the butter sheet from the fridge about 15 minutes before you're ready to fold it into the dough

Dust a work surface with flour and transfer the dough (now fermented for 90 minutes at room temp) onto it.

Degas the dough by pressing it gently to remove excess gas.

Roll the dough to approximately 18"long x8" wide (45x20cm). I use a French style rolling pin to do this as it gives me more control.

Remove 1 of the 2 pieces of parchment from the butter sheet, then flip the butter parchment (butter side down) over and place the butter block on the bottom two-thirds of the dough.

Rub your hands along the parchment to gently warm butter to help facilitate separation from the parchment.

Peel off the parchment paper from the butter block.

Fold the top third of the dough over the middle third, then fold the bottom third over the top and middle.

Pat down the folded dough to seal it together.

Rotate the package 90 degrees and roll it out to 18" (45cm) length again.

Fold one side of the dough into the middle, then fold the other side into the middle.

Fold both sides over each other, creating a book-like shape.

Use your rolling pin to pound the top of the dough, helping to seal the folds together

Transfer the folded dough to a sheet tray, cover, and refrigerate for 30 minutes.

Remove the dough from the refrigerator and place it on a lightly floured surface.

Start by using your rolling pin to pound out the dough to get you started. Pounding as opposed to rolling helps to spread out the dough without smearing the butter. Finish by rolling the dough out to a rectangle again approximately.

Place on a sheet tray, cover, and refrigerate once more for about 20-30 minutes.

Remove from the refrigerator and roll one last time until the rectangle is about 12"x15" (30x38cm)

Use a dough scraper or knife to cut of the sides to create a clean, crisp rectangle measuring about 10"x12" (25x30cm), then cut that rectangle into 8 pieces that are about 3"x5" (8x13cm). Refrigerate these pieces for another 10 minutes if any butter is smearing around the edges at this point.

Use a serrated knife to cut the chocolate bar into long strips (about 3"/8cm ish pieces) and stack two bars at one end of each piece of dough.

Roll the dough tightly around the chocolate pieces from one end to the other, creating a log

NOTE: If you'd like to freeze the pastries for later, you can freeze them just after rolling the dough around the chocolate. When you're ready to bake, allow to proof at room temperature until pastries have thawed and have at least doubled in size, then follow the steps below.

Place the rolled pastries on a baking sheet lined with parchment paper, leaving space between each piece.

Cover the with another sheet tray and let them proof in the fridge for about 90 minutes. They should double in size.

Preheat the oven to 425°F (220°C).

In a small bowl, whisk together the egg and a splash of milk to create an egg wash.

Brush the pastries with the egg wash twice, ensuring they are well coated.

Bake the pastries in the preheated oven for 16-18 minutes, or until they are golden brown and puffed up