Combine the hazelnuts, the mascarpone,
Fold the crêpes into quarters.
Heat the simple syrup, the orange juice, the lemon juice, and the salt in a large sauté pan over medium heat. Place half of the crêpes in the pan and cook them for 15 to 30 seconds, until they are warmed through. Remove them from the pan and keep them warm on a covered plate while you cook the remaining crêpes. Remove the second batch of crêpes from the pan and place them with the first batch. Add the butter to the pan and continue to cook the sauce until it begins to thicken.
Place two crêpes on each plate. Spoon some sauce over the crêpes and top with the hazelnut mascarpone cream.
Drizzle the warm chocolate sauce over the crêpes. Serve immediately.