Cake with Walnuts and Chocolate

Description
In Romanian: Prajitura cu nuci si ciocolata

Ingredients

 * 1 lb/500 g butter,
 * 1 lb/500 g confectioner's sugar,
 * 100 walnuts,
 * shelled and ground,
 * juice from 1 lemon and a little lemon peel,
 * 1 egg, 10 oz/300 g grated chocolate or 50 g cacao,
 * butter and bread crumbs to grease and dust the pan

Directions

 * 1) cream the butter with the Sugar, add beaten yolks, lemon juice, lemon peel, chocolate (grated or melted with 1 tablespoon hot water). In the end, add whipped egg whites and walnuts, mixing gently.
 * 2) The baking pan must be well buttered and sprinkled with fine bread crumbs.
 * 3) Bake at medium heat for 20-25 minutes. As soon as it is done, remove from the oven and cut into squares, rectangles or diamonds.