1. Mix the lukewarm milk with the dried yeast and let sit for about 8-10 minutes so it can bubble up a bit.

2. Mix the flour with sugar, and salt in a large bowl. Add the yeast milk, water, and butter and knead for about 5-6 minutes until you get a nice smooth dough that is coming off the sides of the bowl. Cut off about 6.3 oz. (180g) of the dough. Wrap the rest of the dough very loosely into plastic wrap and place in a large bowl in the fridge. Mix the cocoa powder and water for the chocolate layer until you get a very thick chocolate paste – do not add too much water. Mix that chocolate paste with the dough piece you cut off and knead until you get a dough that is evenly brown due to the chocolate paste. Wrap loosely into plastic wrap and place in the fridge as well. Let both dough portions rest in the fridge for at least 4 hours (or overnight).

3. Draw a 17x17cm square on a large piece of baking parchment, flip the paper and place the butter inside that drawn square (you should be able to still see it through the paper). Fold the paper over the butter along the sides of the square to create a package that seals in the butter completely. Use a rolling pin to press and roll out the butter into that square shape to get one even layer. Place in the fridge along with the dough.

4. Take out the large piece of dough and roll it out on a lightly floured surface to a rectangle that is roughly double the size of the butter layer – about 35x18cm. Remove any flour on the surface with a brush, then place the butter layer (without the paper) on top of the dough in the center of the rectangle and fold the dough on the longer sides over the butter. Pinch the edges together to seal in the butter completely. Gently press and roll out the dough-butter package to a rectangle of roughly 50x20cm. Once again remove flour with a brush. Fold the sides of the rectangle towards the center to create an (almost square) package and then fold once more in the same direction to create a package that has four layers – this is called a »double turn«. Wrap loosely in plastic wrap and place in the fridge for 1 hour.

5. Roll out the dough once more on a floured surface – this time place the package in front of you, the longer sides should be facing away from you and you should be able to see the four layers of the package in front of you. Roll it out to create a rectangle with a size of about 50x25cm. Remove flour with a brush and fold the longer sides towards the center, but this time you will do a »single turn« by folding about 1/3 on one side towards the center and then folding 1/3 from the opposite side towards the center as well (almost like wrapping a gift box) – you will create a new package with three layers this time. Wrap loosely in plastic wrap and place in the fridge for 1 1/2 hours this time.

6. Roll out the chocolate dough on a floured surface to the same size as the dough package you created earlier with the other dough. Remove any flour with a brush and place the layer on the package and press together. Roll it out to a rectangle with roughly 35x45cm. Cut the rectangle into 35x9cm long strips and these strips diagonally into triangles. Flip the triangles so the chocolate side is facing down and roll them up from the wider side into a croissant. Place with a lot of space in between on two baking sheets, cover with plastic wrap and let rise another 45-60 minutes.

7. While the croissants are rising preheat the oven to 180°C (350°F). When ready place in the oven and bake for 18-20 minutes – switch the baking sheets halfway through. The croissants should have puffed up nicely and have a golden color. Take them out of the oven and let them cool down on a wire rack.