Keep 350 g of butter and 1 egg for next steps.
Using a food processor, mix all the other ingredients slowly for 4 min, then mix them at an average speed for 8 min.
Keep the temperature below 24°C.
Let rest for 15 min at 4°C.
Put some flour on your work surface to prevent the dough from sticking. With a rolling pin, roll out the dough into a big rectangle and pound butter until it’s about 15x15cm. Put it on top of the dough in the center. Fold the 4 flaps of the dough over the butter.
Again, roll out the dough into a big rectangle. First, fold the extremities toward the center and then fold them on top of each other. Let rest for 15 min.
Roll out the dough into a thin rectangle. Cut pieces of 4×15 cm.
Sprinkle with caramel pieces and fold the extremities toward the center and then in 2.
Brush the palmiers with a beaten egg.
Let rest until doubled in bulk and put it in the oven at 200°C for 10 to 15 min.