8 oz chestnuts, peeled
3 oz sugar
4 tblspoons water
2 tbls cocoa powder
2 tbls rum, brandy or other spirit
Icing sugar as needed
Simmer chestnuts in water until cooked - about 5-10 minutes. Meanwhile boil the sugar and water until a drop sets instantly on contact with cold water - if you do this too early you end up with a mass of sugar and water which you can't get out of the saucepan, so have everything else ready first.
Put chestnuts, cocoa powder and the sugar syrup into the food processor and blend. Add spirit as liked (I said 2 tbls, but you could use less or more), or perhaps a little coffee essence... If it is a bit runny, add some icing sugar. Then make into truffle-sized balls and roll in cocoa powder or mouse droppings (sorry, I mean chocolate vermicelli - sprinkles, in American usage, I think), and store in the fridge.