Preheat oven to 300 degree F. Draw two 8-inch circles on a foil-lined baking sheet. In a large mixing bowl combine egg whites, vanilla, and cream of tartar. Beat egg white mixture with an electric mixer on medium speed until soft peaks form (tips curl). Gradually add 1-1/3 cups of the sugar, a tablespoon at a time, beating about 7 minutes on high speed until stiff peaks form (tips stand straight) and sugar is almost dissolved. Gently fold in the 1 cup nuts. Spread half of egg white mixture over each circle on baking sheet. Bake 35 minutes. Turn off oven. let meringues dry in oven, with door closed, 1 hour.
To assemble, in a small saucepan melt chocolate and 1 tablespoon of the margarine or butter over low heat, stirring constantly. Set aside to cool. In a medium mixing bowl beat cream cheese with remaining margarine until smooth; beat in remaining sugar. Gradually add cream, beating at low speed until combined, then at medium speed just until soft peaks form. Stir in coffee liqueur. Carefully peel meringues from foil. Place one on serving plate. Drizzle with the chocolate. Spread with half of whipped cream mixture. Place second meringue on top. Spread with remaining cream mixture. Sprinkle with 1/4 cup coarsely chopped nuts. Cover loosely. Chill for 2 to 24 hours. Serves 12 to 16.