Vanilla marrons glacés

Carefully drain the chestnuts and put them in a cooking basket. Split the vanilla pod and scrape out the seeds. In a pan that fits the basket, combine the water, 750 g sugar, vanilla pod and seeds. Boil for 5 minutes. Lower the chestnut basket into the syrup and simmer for 3 minutes. Turn off the heat, cover and leave in the syrup for 24 hours.

Divide 500 g sugar into 4 equal portions. The next day, lift out the basket and let it drain over the syrup. Add one sugar portion to the syrup and bring to the boil. Lower the basket back in and simmer for 3 minutes. Turn off the heat, cover and leave for 24 hours. Repeat daily until all 4 portions have been used.

After the last rest, lift out the basket. Add the remaining 250 g sugar to the syrup and bring to the boil. Lower the chestnuts back in, simmer for 3 minutes and turn off the heat. Cover and leave for another 24 hours. The chestnuts should become glossy and translucent.

Carefully place the chestnuts on a rack and drain for at least 2 hours. Gently warm the syrup, remove the vanilla pod and dissolve the icing sugar in it. Set the rack over a tray. Spoon the syrup over the chestnuts, then transfer them to baking paper. Dry for about 60 minutes until the surface is no longer sticky.