Blueberry lemon cake with coconut crumble topping

1 . Stage

Heat oven to 180C/fan 160/gas 4 and grease and line a 20 x 30 cm cake tin with baking parchment. Beat together 250g of the butter with 250g sugar and the lemon zest until light and fluffy. In a separate bowl, break up 4 eggs with a fork, then gradually beat into the butter and sugar mixture, adding a spoonful of flour if it begins to curdle. When the eggs are incorporated, fold in the flour and a third of the blueberries, then spoon into the tin. Flatten the surface with a spatula, sprinkle over another third of the blueberries, and bake for 20 mins until the surface is set.

2 . Stage

To make the topping, melt the rest of the butter, then stir in the coconut and remaining sugar and eggs until combined. Warm the lemon curd gently for a few mins in a small pan until it is runny and pourable.

3 . Stage

After the initial baking, scatter the remaining blueberries over the top of the cake, drizzle over the lemon curd, and crumble over the coconut mixture. Bake for a further 20-25 mins until the coconut is golden. Leave the cake in the tin to cool. Cut into 16 squares and store in a tin, interlined with greaseproof paper.