1. Preheat the oven to 200°C. Sift the white and wholemeal flours and the baking powder into a large bowl, tipping in any bran left in the sieve.

2. Stir in the sugar. Add the butter and rub it in with your fingertips until the mixture resembles fine breadcrumbs.Stir in the lemon zest, then very gently stir in the blackberries. Do not overmix, as the blackberries can easily become crushed.

3. Lightly stir in the buttermilk using a round-bladed knife, again being careful not to crush the blackberries. If there are any dry bits of dough in the bottom of the bowl, add a little more buttermilk. As soon as the mixture comes together in a soft dough, lift it from the bowl onto a floured surface and knead gently 2 or 3 times only, just to form a rough ball.

4. Pat out the dough carefully with your hands to make an 18 cm round. Transfer it to a greased baking tray. Mark into 8 wedges with the back of a knife and sprinkle with a little extra white flour. Bake for 20–25 minutes, or until pale golden and risen. Serve warm, broken into the marked wedges. These scones are best eaten freshly baked, or on the day they are made, but will still be good the next day; store them in an airtight container.

* Each scone provides 754 kJ, 180 kcal, 4 g protein, 6 g fat (4 g saturated fat), 29 g carbohydrate (9 g sugars), 2 g fibre