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,
 * 1/2 teaspoon baking soda,
 * 1 teaspoon vanilla,
 * flour as needed,
 * 2 oz/50 g ground walnuts,
 * 6 whipped egg whites,
 * 1 cup sugar,
 * marmelade

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 marmelade 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 marmelade, 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.