Blackberry Fool

1. For the biscuits, preheat the oven to 200C/180C fan/Gas 6 and line two large baking trays with parchment. Scatter the hazelnuts over a tray and roast for 6 to 8 minutes until golden-brown, watching closely so they do not burn, then tip onto a board and leave to cool.
2. Beat the butter and sugar in a large bowl until light and creamy. Roughly chop the cooled nuts and add them with the lemon zest, flour and baking powder, stirring (and using your hands if you need to) until it comes together into a ball.
3. Divide the dough into 24 even pieces and roll into balls, spacing them well apart on the trays, then press each one to flatten to about 1cm thick.
4. Bake one tray at a time for 12 minutes until very pale golden-brown, then leave to cool on the trays. They will be soft from the oven but crisp up as they cool. Store in an airtight tin and eat within five days.
5. For the fool, rinse the blackberries, put them in a non-stick saucepan and sprinkle over the caster sugar. Stir in the lemon juice and heat gently for two minutes until they start to soften and release their juices, then remove and set aside 12 berries for decoration.
6. Simmer the rest very gently for 15 minutes, stirring regularly, until very soft, then press through a sieve over a bowl, using the bottom of a ladle to extract as much purée as you can. Leave to cool and discard the seeds. You should have around 325ml of purée.
7. Whip the cream and yogurt in a large bowl until soft peaks form, taking care not to overdo it, as the fruit's acidity will thicken it further. Once the purée is completely cold, adjust the sweetness to taste, pour it into the cream and yogurt, and stir just once or twice until lightly marbled.
8. Spoon into wide glass dishes or one large bowl, keeping the marbling. Scatter over a few tiny mint leaves and the reserved blackberries, sprinkle with a little sugar if you like, and serve with the hazelnut biscuits.

Tips from the ZestyPlate Kitchen

• Push the cooked blackberries through a sieve thoroughly to leave the seeds behind and the purée silky.
• Cool the purée completely before it meets the cream. Add it warm and it will slacken the whole thing.
• Fold with just a stir or two so you keep that pretty marbled ripple rather than turning it uniformly pink.
• Stop whipping the cream early; the fruit's acidity firms it up further once the two are combined.