200g unsalted butter, plus extra for greasing
200g caster (superfine) sugar
4 medium eggs, lightly beaten
200g self-raising flour
1 tsp baking powder
finely grated zest and juice 1 lemon
For the icing
100g icing (powdered) sugar
finely grated zest 1 lemon, plus the juice 1⁄2
1 Preheat the oven to 180°C/350°F/Gas mark 4. Lightly grease a 26 x 20cm (101⁄2 x 8in) baking tin and line it with baking parchment.
2 Place the butter in a large mixing bowl, add the sugar and beat until pale and fluffy. Gradually add the egg, beating well between each addition.
3 Sift over the flour and baking powder and gently fold into the batter, until just combined. Stir through the lemon zest, juice and 200g (11⁄2 cups) of the blueberries until well dispersed, before spooning the mixture into the prepared tin. Smooth the mixture with the back of a spoon then bake in the oven for 20–25 minutes, until lightly golden and a skewer inserted into the centre comes out clean. Set the cake aside to cool while you make the icing.
4 Sift the icing sugar into a mixing bowl and add a couple of teaspoons of the lemon juice. Gradually mix the sugar into the lemon juice, adding a little more juice as necessary, until you have a fairly runny mixture. Stir through the lemon zest then drizzle over the cake. Scatter over the remaining blueberries and cut into squares to serve. This will keep in an airtight container for up to 2 days (without the blueberries on top).
Recipe from Cath Kidston cookbook: Teatime (Quadrille, £15)