Drain the cherries on a sieve, collecting the juice.
Caramelize sugar with 1 tablespoon water in a saucepan over medium heat until golden brown. Deglaze with 200 ml of the cherry juice, add balsamic vinegar. Mix 2 tablespoons of the cherry juice with the cornstarch, add to the heated cherry juice and bring to the boil briefly. Add the cherries, remove the pan from the heat and let it cool down.
Mix the mascarpone with the espresso powder and sugar until the sugar has dissolved.
Whip the cream until stiff and fold it carefully into the mascarpone cream.
Pour the cream into glasses and chill for 1 hour. Spread the compote on top. Crumble the cantuccini and sprinkle on top.