Dissolve espresso in 125 ml of boiling water. Add 1 tablespoon of sugar and the liqueur, allow to cool. Drain the cherries. Mix the mascarpone, quark, lemon peel and 4 tablespoon sugar.
Line the bottom of a square shape (approx. 15 x 15 cm) with half of the cantuccini. Drizzle half of the espresso over it and spread half of the mascarpone cream on top. Spread the cherries on top of the cream, except for a few to decorate. Place the rest of the cantuccini on top and drizzle with the rest of the espresso. Spread the rest of the cream on top. Chill for about 3 hours. Dust the tiramisu thickly with cocoa, decorate with the remaining cherries and chocolate shavings.