Photograph: Martin Poole
- 12 sponge fingers
- 75 ml espresso, cooled
- 150 g half-fat crème fraîche
- 250 g quark (see below)
- 3 tbsp Kahlua coffee liqueur
- 2 tbsp caster sugar
- 1 square of dark chocolate (minimum 70% cocoa solids)
Divide half the sponge fingers among 4 individual serving dishes or glasses, breaking them up to fit snugly over the base of the dishes. Drizzle over half of the cooled espresso.
In a bowl, beat together the crème fraîche, quark, Kahlua and sugar until smooth; spoon half over the sponge fingers. Repeat with another layer of sponge fingers, espresso and crème fraîche mixture. Grate over the chocolate and chill for at least 1 hour.
Get ahead: assemble up to 4 hours ahead; cover and chill.
Kitchen secret: quark is a virtually fat-free soft cheese – a good, tangy replacement for the mascarpone that makes a traditional tiramisu so high in calories.