Preheat the oven to 180C/160C Fan/Gas 4.
Grease and line your loaf tin.
Cream together the butter and sugar until pale, light and fluffy. Add the lemon zest. Gradually add the beaten eggs, mixing well between each addition.
Sift the flour and baking powder into the bowl. Add the ground almonds, salt, milk and the juice from 1 lemon. Mix again until smooth and thoroughly combined.
Spoon one third of the mixture into the prepared tin, level the surface and scatter with one third of the blueberries. Repeat this layering a further two times until all of the mixture and blueberries have been used up.
Bake on the middle shelf of the oven for about 1 hour or until golden-brown and a skewer inserted into the middle of the cake comes out clean. Leave to cool in the tin for 10 minutes.
Mix the remaining lemon juice with the granulated sugar in a bowl. Spoon the lemondrizzle over the top of the cake and leave in the tin until completely cold.