Preheat the oven to 180°C/350°F. Weigh out the self-raising flour, butter, and light brown sugar and put them in a mixing bowl. Rub the ingredients together with your fingers until it forms the texture of fine breadcrumbs.
250 g self-raising flour, 175 g unsalted butter, 175 g light brown sugar
Add the eggs and mix well with a wooden spoon until well combined.
2 large eggs
Add most of the blackberries (reserve a few for the top of the cake) and all the lemon zest to the cake batter and then stir through gently. Don’t mix too much as the blackberries might disintegrate and make the cake mixture turn grey!
150 g blackberries, 1 lemon
Grease and line a 2 lb (900 g) loaf tin. Spoon the cake mixture into the lined tin. Press the remaining blackberries into the top of the mixture.
Bake for 50-55 minutes or until a skewer or cake tester comes out clean from the centre. Cover the cake with foil from around 40 minutes to stop the top of the cake browning too much.
Remove the tin from the oven once fully cooked and allow to cool for about 5 minutes. Remove the cake from the tin using the lining paper, peel off the paper, and leave the cake to cool fully on a cooling rack.