Start by making the dough. In a bowl mix flour, sugar, salt, yeast and water. Knead until the dough is elastic and smooth.
Set the dough into a bowl, cover and allow to rest for 30 minutes in the fridge.
Meanwhile prepare the margarine block. Cut the margarine into thick slices and place them side by side onto a sheet of baking paper to form a 20 x 20 cm (8 x 8 inches) square.
Then wrap the margarine with the baking paper (see pictures above) and using a rolling pin, roll out the butter into a perfectly levelled 20 x 20 cm (8 x 8 inches) square.
Set in the fridge.
Take the dough out of the fridge and form it (using our hands) into a 25 x 25 cm (10 x 10 inches) square.
Use a rolling pin to roll it out into a 45 x 25 cm (18 x 10 inches) rectangle.
Place the block of margarine on one side of the rectangle.
Fold the other side of the dough up and over the margarine.
Now gently roll out the dough forming a rectangle of 45 x 25 cm (18 x 10 inches).
Grab the bottom of the dough and fold it ¾ of the way up the rectangle. Then take the top half and fold it the remaining ¼ of the way until both ends meet.
Then fold the long part over the short one, making a long rectangle.
Wrap the rectangle in baking paper and let it rest for 1 hour in the fridge.
Unpack the dough and roll it out forming a large 60 x 25 cm (24 x 10 inches) rectangle.
Grab the bottom of the dough and fold it ⅓ of the way up the rectangle.
Then take the top half and fold it over so that it covers completely the other one.
You should now have a square. Wrap it in baking paper and set in the fridge for 1 hour.
Then use a rolling pin to shape slowly and carefully the dough into a 30 x 50 cm (12 x 20 inches) rectangle.
For large pain au chocolate: cut the dough into 5 large rectangles widthwise and cut the chocolate into 10 sticks.
For regular pain au chocolate: cut the dough in half lengthwise, then cut the dough into 10 rectangles widthwise. Cut the chocolate into 20 sticks.
Then starting at the base of each rectangle, place a stick of chocolate.
Begin rolling, then place a second stick of chocolate and keep rolling making sure the end of each rectangle ends up tucked under the pain au chocolate to hold in place.
Transfer to a baking tray lined with baking paper, leaving some space between each croissant.
Brush the pain au chocolate with soy milk or water, put them in the oven and close it. Allow to rise for 2 hours or until they've doubled in size.
Brush them with oat cream (or maple syrup/soy milk).
Preheat the oven to 200 °C (390 °F) and bake for 15 minutes in the middle of the oven. Bake until the croissants are golden and crispy.
Allow to cool and ENJOY!