Heat oven to 350 degrees. Cut 2 rounds of parchment paper to fit the bottoms of 2 8-inch cake pans. Butter and flour the parchment paper, then butter and flour the cake pans. Line pans with buttered paper.
Meringue: Place egg whites in a large bowl. Beat until stiff. Add sugar and nuts all at once. Fold in gently. Add vinegar and vanilla. Stir to blend. Spoon mixture equally into the 2 prepared pans.
Bake meringue for 40 to 45 minutes or until crusty to the touch. Remove from oven, run a knife around edges and quickly turn upside down on cake racks. Remove pans and peel off paper. Let cool.
Filling and icing: Melt chocolate in 1/2 cup of the whipping cream, stirring until smooth. Set aside.
Whip remaining cup of whipping cream with confectioners sugar until stiff.
Assembly: Place 1 meringue round on a serving platter. Cover with half of whipped cream. Drizzle top with half the melted chocolate. Top with remaining meringue and repeat with whipped cream and melted chocolate. Refrigerate until ready to serve. Makes 6 to 8 servings.
