Whip the egg whites and salt in a clean, dry bowl until they hold a very soft peak. Whip in the remaining sugar gradually, continuing to whip the egg whites until they hold a soft, glossy peak. Stir one-fourth of the egg whites into the batter. Sift one-third of the buckwheat flour over the batter and fold it in, then add another fourth of the egg whites and fold in. Continue alternating the flour and egg whites, ending with the egg whites. Pour the batter into the prepared pan and bake at 350 degrees for about 30 minutes, or until a skewer inserted in the center of the cake comes out dry.
Cool the cake in the pan about 10 minutes, then invert onto a rack to complete cooling. The torta may be prepared several days in advance up to this point. Wrap well in plastic and refrigerate.
To finish, trim the torta evenly with a sharp, serrated knife, if necessary. Invert the cake so that the top is underneath and slice the cake through the middle to make 2 layers. Place the bottom layer on a platter and spread with the raspberry preserves. Place the other layer on the preserves and press well to make the layers adhere. Before serving, dust the cake with the confectioners’ sugar. Store leftovers tightly covered at room temperature.
Confectioners’ sugar for finishing
© 1990 Nick Malgieri. All rights reserved.