to 2 c Chocolate Layers: Preheat oven to 350 degrees. Grease and flour two 23 cm layer pans. Sift flour, cocoa and salt onto waxed paper. In large bowl, beat sugar, butter and eggs with electric mixer at high speed for 5 minutes, or until light and fluffy. Add flour mixture alternately with milk, beating at low speed after each addition. Moisten baking soda with vinegar, and stir into batter along with coffee. Divide batter between the two prepared pans. Bake for 40 minutes, or until toothpick inserted in center comes out clean. Cool 10 minutes. Loosen edges and turn out onto wire rack. Cool completely. Yellow Layer: Preheat oven to 350 degrees. Grease and flour a 23 cm layer pan. Sift flour, sugar, baking powder and salt into small bowl. Add shortening and half C of the milk. Beat with electric mixer at medium speed for 2 minutes, scraping sides often. Add remaining milk and egg; beat 2 minutes longer. Pour into pan. Bake for 35 minutes, or until toothpick inserted in center comes out clean. Cool 10 minutes. Loosen edges and turn out onto wire rack. Cool completely. To assemble cake: Place one chocolate layer on serving plate; spread with half of Caramel Filling. Top with yellow layer; spread with remaining filling. Place second chocolate layer on top. Frost side and top of cake with Vanilla Frosting, making deep swirls. Keep in cool place until ready to serve. Slice into THIN wedges, and serve with vanilla ice cream if desired. Caramel Filling: In medium saucepan, melt butter; add sugar and bring to a boil, stirring constantly. Lower heat, cook and stir for 2 minutes longer. Stir in milk and salt. Remove from heat; cool to lukewarm. Gradually stir in powdered sugar until smooth. Chocolate Frosting: In medium bowl, combine butter, egg, chocolate and corn syrup. Beat until smooth. Add powdered sugar, water and salt. Beat again until smooth and spreadable. If too soft to spread, add more sugar. ----