- Prepare the chestnuts
Wash the chestnuts, removing any that float as they are hollow. Score an X into the bottom of each chestnut. Place them in a saucepan of cold water, bring to a boil and cook for 3 minutes. Drain the chestnuts, then remove the outer skin, the shell. Return the chestnuts to the boiling water and cook for 15 minutes. Turn off the heat. Remove a chestnut from the water and immediately peel off the thin skin. Do the same with all the chestnuts, leaving the unpeeled ones in the hot water. Carefully arrange the chestnuts in the perforated basket of a casserole dish to make draining easier.
- The syrup
Bring the water, sugar and scraped vanilla pod to a boil. Place the basket of chestnuts in the syrup and simmer for 3 minutes. Leave overnight at room temperature. The next day, remove the chestnuts and bring the syrup to a boil for 5 minutes to concentrate the sugar. Dip the chestnuts back in and simmer for another 3 minutes. Leave until the next day and repeat the process 5 times. The chestnuts are candied when a drop of syrup reaches the center of the chestnut. Drain the chestnuts for 1 day on a rack.
- The icing
Make the icing by mixing the icing sugar and the chestnut syrup. Coat each chestnut completely and place it back on the rack. Put the chestnuts in the oven preheated to 220°C for 2 to 3 minutes to harden the icing. Allow to cool. Store away from moisture.
