Lemon Posset with Shortbread Fingers

Ingredients

• 600 ml double cream
• 150 g caster sugar
• 3 lemons, zested and juiced (about 100ml juice)
• 150 g plain flour
• 50 g caster sugar, for shortbread
• 1 pinch salt
• 100 g unsalted butter, softened

Method

1. Tip the double cream and 150g caster sugar into a wide, heavy saucepan over a medium heat. Stir gently until the sugar dissolves and the cream looks glossy, about 3 minutes — wide pan matters here, because the cream needs surface area to boil without climbing the sides.
2. Bring to a rolling boil and let it bubble for exactly 3 minutes, stirring occasionally so the bottom doesn't catch. Watch it like a hawk — cream goes from rolling to over-the-top in seconds. The full 3 minutes is what reduces and concentrates the cream so it sets later; cut it short and you'll have soup.
3. Pull off the heat and stir in the lemon zest and the lemon juice. You'll feel it thicken almost immediately as the acid hits the hot cream — that's the set beginning. Taste it: it should be sharp, sweet, and rounded. A tiny pinch of salt here lifts the lemon and stops the sugar tasting flat.
4. Divide between 4 glasses or ramekins, pouring through a fine sieve if you want it glassy-smooth. Cool to room temperature uncovered, then chill for at least 3 hours, until set to a soft, trembling wobble — firm at the edges, just-quivering in the middle.
5. Meanwhile, heat the oven to 170°C fan. Beat the softened butter and 50g sugar with a wooden spoon until pale and fluffy, 2–3 minutes. You're not whipping air in — you're working the sugar into the butter so the shortbread bakes short and sandy, not greasy.
6. Work in the flour and a generous pinch of salt until it comes together into a smooth, slightly crumbly dough. Don't skip the salt — without it the shortbread tastes of nothing but sweet butter. Press together with your hands; stop the moment it holds.
7. Roll out to 1cm thick on a lightly floured surface, then cut into fingers about 2cm wide. Lift onto a lined baking tray with a little space between each — they spread a touch as the butter melts.
8. Bake for 15–18 minutes, until pale golden at the edges and sandy-pale on top. They'll feel soft coming out of the oven; leave them on the tray to cool and firm up — that's when the crunch sets.
9. To serve: bring the possets straight from the fridge, scatter each one with a fine flurry of extra lemon zest, drop a few raspberries on top if using, and tuck the shortbread fingers alongside for dunking.