Cake with Walnuts and Marmalade

Description
In Romanian: Prajitura cu nuci si marmelada

Ingredients

 * 1 cup sour cream
 * 1 cup lard or butter
 * 1 cup confectioner's sugar
 * 4 yolks
 * ½ teaspoon baking soda
 * 1 teaspoon vanilla
 * flour as needed
 * 2 oz / 50 g ground walnuts
 * 6 whipped egg whites
 * 1 cup sugar
 * marmalade

Directions

 * 1) Cream 1 cup of sugar with the butter or lard and 4 yolks, add sour cream, baking soda and vanilla, mix well, add flour and knead a medium soft dough.
 * 2) Roll a sheet the size of the baking pan, place in the pan and spread marmalade on it.
 * 3) Whip 6 egg whites, gradually add 1 cup sugar, then add the ground walnuts. Mix gently.
 * 4) Place this mixture on top of the dough with marmalade, smooth into a uniform layer and bake at medium heat to start with and then at higher heat.
 * 5) When done, cut into squares or rectangles.