For the chestnut cakes, boil the peeled chestnuts with water and 1 tsp. sugar in a saucepan for ten minutes on low heat, then take out 25 of them, cook the rest for another ten minutes on low heat. Pour away the cooking water. Drain the chestnuts properly, mash them and let them get cold.
Beat eggs with whole cane sugar, salt and lemon rind in a bowl until creamy. Mix in white spelt flour and chestnut puree, knead into a dough and let rest in the refrigerator for thirty minutes.
Cut dough with a teaspoon, form balls and place on a greased baking sheet, spacing each about 2 cm apart. Cut whole chestnuts in half and press half a chestnut into each ball.
Bake in a preheated oven at 180 °C , in a hot-air oven at 150 °C , for ten to fifteen minutes.
Remove the chestnut cakes and let them cool on a cooling rack.