Chocolate puff pastry is always a treat! This is the best recipe I have ever used because it uses cocoa powder, which always imparts the best flavor. Use the best quality ingredients you can afford because puff pastry contains very few ingredients that all need to shine on their own.
PASTRY RECIPE HELP
INGREDIENTS
420 grams unbleached all purpose flour
185 grams cold water
2 tsp salt
70 grams, unsalted excellent quality butter, melted and cooled
425 grams unsalted excellent quality butter, slightly softened
50 grams natural cocoa powder, sifted
INSTRUCTIONS
Place flour on a working surface and make a well in the center. Dissolve the salt into the cold water and add this to the center of the flour well. Slowly start mixing the flour and the water together with circular motions and always working in the center so the water is absorbed by the flour and we work neatly. When they are mixed, add the melted and cooled butter.
Knead the dough for about 5 minutes. It will not be a super smooth dough at this point but don't worry because we will keep developing the gluten as we roll the dough. Wrap the dough in plastic wrap forming a rectangle that is approximately 6 inches long on one side. Refrigerate overnight.
To make the lock-in butter, cream the butter with the paddle attachment until smooth but still cold. Add the sifted cocoa powder and cream until the cocoa is absorbed by the butter. Wrap in plastic wrap also forming a rectangle that is a bit smaller than the previous one. Refrigerate overnight.
The next day, pull the dough out of the refrigerator and roll to a rectangle that is about 1 cm thick (1/3 inch) and about 30- x 18-cm long (12- x 7-inches). Remove the lock-in butter out of the fridge. It will be harder than the dough but we need to have both right about the same consistency, so pound the butter with a rolling pin to soften it slightly.
Place the slightly softer butter on top of the right half of the dough rectangle. Fold the left side of the dough over the butter creating a packet. Seal in the edges. If necessary, press the dough down so the butter reaches every corner of the dough. We want the butter to spread evenly all over to create even layers. Place the dough on a sheet pan, cover it with plastic wrap and refrigerate for 2 hours.
Remove the dough from the refrigerator and roll it to a rectangle that is 3 times wider than tall, about 52- x 18-cm (7- x 21-inches). Fold the dough like a letter, bringing the right third over the middle third and folding the left on top of it. Wrap in plastic and refrigerate for 2 hours. This was the first turn and make sure to mark it somewhere so you don't lose track of how many folds you have done.
Repeat this procedure 5 more times for a total of 6 letter folds, always rolling the dough with the open edges to the left and right of you. Refrigerate the dough after each turn. Use flour when rolling but brush off any excess after each turn to avoid getting too much flour on the dough. If the dough rips a bit and the butter is exposed, don't worry, try to patch it as well as you can but keep going. After all the folds are done, it will not matter that much.
After the last fold, refrigerate the dough overnight.
STORAGE
You can use it the next day or what I did was roll it into two sheets and froze them until I was ready to use them. This dough will be good in the refrigerator for a couple of days and up to one month in the freezer.
Recipe adapted from Pierre Hermes' Chocolate Desserts.