Place the chestnuts on a baking tray lined with baking paper.
Roast for approx. 20 mins. in the centre of an oven preheated to 200°C. Remove and leave to cool. Roughly chop 60 g of them and set aside.
In a food processor, finely grind the remaining chestnuts and transfer to a bowl.
Add the flour, salt and dried yeast, mix together. Pour in the water and maple syrup. Using the dough hook on a hand mixer, knead into a soft dough for approx. 5 mins. Cover the dough and leave to rise at room temperature for approx. 1 hr.
Ease four sides of the dough away from the edge of the bowl using a dough scraper, pull upwards in the bowl and allow to fall in the middle. Cover the dough and leave to rise again for approx. 20 mins. Repeat this step two more times.
Place a baking tray in the centre of the oven. Preheat the oven to 240°C. Place the dough on a well-floured surface, cut the dough in half and shape each half into an oblong baguette. Place the baguettes on a sheet of baking paper, make approx. 3 diagonal cuts into each baguette using a sharp knife, slide onto the hot baking tray.
Approx. 15 mins. in the centre of an oven preheated to 240°C. Reduce the heat to 200 °C and bake for a further 10 mins. Remove the baguettes from the oven, leave to cool on a cooling rack.