Instructions

1. In a small bowl, combine the room-temperature water, sugar, and yeast. Stir and let sit for 10-15 minutes until it becomes frothy.
   
2. Meanwhile, in another small bowl, mix the room-temperature cream and salt.
   
3. When the yeast has activated (it begins to produce bubbles and foam on the surface), sift the flour into a large bowl and add the contents of the two small bowls.
   
4. First, use a spoon to combine, then use your hands to knead the dough until smooth (about 8-10 minutes). Form the dough into a ball, place it in the bowl, and cover the bowl with plastic wrap. Let the dough rest at room temperature for 2 hours.
   
5. After an hour and a half, take the butter out of the fridge and let it soften at room temperature for 10-20 minutes. Once softened, place it between two sheets of plastic wrap and roll it out into a 10x10 cm (4x4 inches) square.
   
6. After another half hour, flour the work surface, remove the dough from the bowl, and roll it into a 25x10 cm (10x4 inches) rectangle.
   
7. Remove the butter square from the plastic wrap and place it in the center of the dough. Fold the edges of the dough over the butter, joining them in the center.
   
8. Wrap the dough in plastic wrap and refrigerate for 15 minutes.
   
9. After 15 minutes, remove the dough from the plastic wrap and roll it out in the direction of the butter “seal” until it forms a rectangle that is 2-3 times longer than the original dough.
   
10. Fold the dough into thirds: cover the butter “seal” with the bottom third of the dough, then fold the top third over it. Wrap in plastic wrap and refrigerate for 30 minutes.
    
11. After 30 minutes, remove the dough from the plastic wrap and roll it out from one open edge to the other, maintaining the same dimensions as the previous rectangle. Fold into thirds again, wrap in plastic wrap, and refrigerate for another 30 minutes.
    
12. After 30 minutes, the previous step one more time, but refrigerate the dough for at least 2 hours this time.
    
13. After this time, flour the work surface and roll out the dough into a 30x20 cm (12x8 inches) rectangle, trying to roll from one open edge to the other and turning occasionally to flour as needed.
    
14. Cut the dough into triangles with a base of 10 cm (4 inches). Make a small incision at the base of each triangle, stretch the edges slightly, and gently roll it into a croissant shape. You should be able to make 3 full turns.
    
15. Place the croissants on a baking sheet lined with parchment paper and leave them in the oven with the light on for an hour and a half. (If you wish to bake the croissants the next morning, cover the baking sheet with plastic wrap and refrigerate it; in the morning, take it out and let it sit at room temperature for an hour and a half.)
    
16. Preheat the oven to 160°C/320°F (140°C/280°F for a convection oven).
    
17. Meanwhile, whisk the egg yolk in a small bowl and brush it over the tops of the croissants.
    
18. Bake the croissants in the preheated oven for about 30 minutes, checking them occasionally but without opening the oven door, until golden brown.