Lemon & blackberry traybake

Preheat the oven to 190ºC, gas mark 5. Grease and line a 20cm square baking tin with baking parchment. Put the soured cream and sugar in a bowl and use a balloon whisk to combine; whisk in the eggs 1 at a time. Add the oil and the rest of the cake ingredients; mix into a smooth batter. Transfer to the lined tin.

In the same bowl, use a large spoon to mix the blackberries with the sugar, cornflour and lemon juice so the berries get coated all over and purple liquid starts to seep out. Dot the berries over the cake (leaving the excess liquid behind) so they are evenly distributed; push into the batter a little. Bake for 20 minutes. Rotate the tin and bake for another 10-15 minutes. Meanwhile, for the icing, in a small bowl mix the lemon juice and icing sugar with a balloon whisk until it dissolves.

Remove the cake from the oven; it should feel bouncy to the touch. Brush all over with the icing. Cool in the tin for at least 30 minutes before slicing and serving warm or at room temperature