-coarsely chopped Preheat oven to 350 degrees. Butter and flour a 10-to 12-cup fluted tube pan. In a large bowl, using a hand-held electric mixer set at high speed, beat the butter until creamy, about 1 minute. Add the sugar and continue beating at high speed until light and creamy, about 2 minutes. Sift together the flour, salt, baking soda, and baking powder. At low speed, beat in half cup of the flour mixture, then beat in 1 of the eggs. Beat in another half cup of the flour mixture, then 1 of the remaining eggs. Repeat with another half cup of the flour mixture, and the last egg. Beat in the remaining flour along with the sour cream and vanilla. Using a spatula, fold in the walnuts and chocolate. Transfer the batter to the prepared pan and smooth the surface. Bake for 45 to 55 minutes in the preheated oven until the cake begins to shrink from the sides of the pan and a toothpick inserted in the center comes out clean. The surface will crack. Remove the cake from the oven and let cool for about 10 minutes in the pan, then turn it out onto a wire cake rack. Cool completely before serving. Serves 12.