Almond and Limoncello cake

Almonds and Limoncello - what could be better! I got this recipe off a friend of mine in Taormina, Sicily - the translation should be fine but i didn't convert the metric - there's the converter on my site that you can use!
I used Sicilian Limoncello  - homage to Lucia!!!

Ingredients:

350 gms finely ground almonds
200 gms sugar
200gms flour
Grated rind of a lemon
4 eggs
1/2 cup limoncello
2 tsp baking powder


Method
Beat the eggs with the sugar till you get a white foam
Add the lemon rind and a pinch of salt
Add the ground almonds, the sifted flour and the baking powder
Put into a greased pan and bake for 40 mins at 170C
When done sift powdered sugar on top.