This cake is very fluffy and tasty. Preheat the oven to 180C, grease and line a 15 cm x 25 cm leaf tin with baking parchment.
In a big bowl beat together the butter and sugar until pale and fluffy. Gradually beat in the eggs, one at a time. Sift the flour and baking powder, then add in the butter mixture. Fold the ground almonds as well. Beat well to get smooth batter. Slowely add the lemon juice and zest.
Spoon the batter mixture into the prehated tin and bake for 45-50 minutes.
Cool in the tin for 10 minutes, then invert on to a wire rack and leave to cool.
Put the sugar cubes into a small bowl with the juice of 1 1/2 lemon juice and the pared zest. Soak for 3 minutes, then use the back of the spoon to roughly crush the sugar. Spoon oven the cake.