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 cocoa
 * 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.