Chop up the amarettini, preferably in a freezer bag. Remove a few tablespoons of the cherry juice from the glass of cherries and mix with the cornstarch. Bring the remaining cherry juice to the boil with sugar and a lot of cinnamon. Then add the cornstarch and stir quickly so that it doesn`t clump. Now stop boiling and add plenty of kirsch to the mixture. Mix the mascarpone in a bowl with the amaretto until smooth. Now fill either a glass casserole dish or small glasses one after the other with amarettini, cherry mixture and mascarpone. Chill until ready to eat, preferably longer than 2 hours.