Preheat oven to 180ºC Butter bottoms of 3, 23 cm pans. Line bottoms with waxed paper. Mix: flour, salt and soda in small bowl. Cream: Butter in large bowl until light. Add: sugar gradually and beat until fluffy. Add eggs, one at a time beating well after each addition. Beat in yolks and then melted chocolate Mix in dry ingredients and buttermilk, alternately beginning and ending with dry ingredients. Divide between pans. Bake until wooden pick comes clean (about 25 minutes). Place on racks for 5 minutes. Unmold cakes using pointed knife to loosen sides, place on paper towel lined racks and cool completely. Peel parchment off cooled cakes. Place on platter: place 1 cake layer on platter add stripes of waxed paper under edges. Spread: 0.75 C frosting on top. Repeat for other layers. Remove: Waxed paper strips Add: Walnuts decoratively to top edge and center. ----