My blackberry friand recipe is baked in one large dish rather than as individual cakes. I like it this way, poised somewhere between pudding and cake, served warm from the oven, in generous, fruit-studded spoonfuls. Keep a careful eye on the browning butter. It should be a rich hazelnut brown, but no darker. If there are any brown speckles, pour the butter through a fine sieve before using it.
hazelnuts 100g, skinned
plain flour 50g
icing sugar 180g
lemon zest 1 tsp
egg whites 5
blackberries and raspberries 250g
Set the oven at 160C fan/gas mark 4. Line a 24cm baking dish with baking parchment. Melt the butter in a small pan over a moderate heat. Watch carefully as the butter first froths and then calms down and starts to turn deep gold. Once it is walnut coloured and smells nutty and toasted, remove immediately from the heat and set aside.
Toast the hazelnuts in a shallow pan until they are golden. Move them around regularly to brown evenly. Tip into a food processor and reduce to fine crumbs.
Sift the flour and icing sugar into a large mixing bowl, then stir in all but 1 tablespoon of the ground hazelnuts. Stir in the lemon zest. In a separate bowl, beat the egg whites until they reach a soft, sloppy foam.
Make a deep well in the flour and sugar, then add the beaten egg whites and the melted butter. Combine everything lightly but thoroughly, then pour into the prepared dish. Scatter the blackberries and raspberries over the surface, then the reserved ground hazelnuts.
Bake in the hot oven for 35 minutes until risen and golden brown. The surface should be lightly crunchy; the inside soft and spongy. Remove from the oven and leave to settle for 10 minutes before serving.
Nigel Slater is the Observer’s food writer