Gâteau Lyonnais

Olivier de Serres, often called the father of French agriculture, wrote in 1599 of the chestnuts of Lyon, ‘which is known throughout France for its trade in this fruit.’ If using fresh chestnuts instead of canned chestnut purée for this recipe, peel the chestnuts* and simmer them until soft in a mixture of milk and water. Then drain and purée in a food processor or blender.