Preheat oven to 170°F C. Grease and line the base of the pan.
Beat the eggs with the sugar until thick, then add the ground almonds, the zest and baking powder and mix well.
Pour into prepared pan and bake for 50/60 minutes or until nicely browned on top and a skewer comes out clean when inserted in the top of the cake. Leave the cake to cool slightly (for ten minutes or so), then make holes in the top of the cake with a skewer and drizzle the 1/2 cup juice over the top of the cake so the juice trickles into the cake through the holes. This makes the cake nice and moist.
The cake mellows with a little time and can be prepared up to 48 hours in advance. It looks lovely with fresh berries.