Sieve flour into a pot for tartlet dough. Add butter, rested in room temperature, brown sugar and yolk, and knead them. Lubricate small tart molds and place the dough inside it. Cover it with oil-resistant wrapping paper, or with garbanzos to prevent its swelling. Let it cook in already warmed oven at 180 0C temperature for 10-15 minutes. Take it out of the oven and remove oil-resistant wrapping paper or garbanzos. Spread mashed chestnut over tartlets. Melt cream and chocolate together with bain-marie style for the dressing. Smear the dressing over tartlets.
For the dressing to become firm let it rest for 1-2 hours, then serve it.