CHOCOLATE-MARSHMALLOW RIBBON CAKE

Steps:

• Heat oven to 375°F. Line 15x10x1-inch pan with foil; grease generously. In large bowl, mix flour, cocoa, baking powder and salt; set aside.
• In small bowl, beat eggs with electric mixer on high speed about 3 minutes or until very thick and lemon colored. In large bowl, gradually beat 1 cup granulated sugar into eggs. On low speed, beat in 1/3 cup water and the vanilla. On low speed, beat in flour mixture just until batter is smooth. Pour into pan, spreading batter to corners.
• Bake 12 to 15 minutes or until top springs back when touched lightly. Generously sprinkle clean towel with powdered sugar. Run knife around side of pan to loosen cake; turn upside down onto towel. Carefully remove foil. Cool cake completely, about 30 minutes.
• In 3-quart saucepan, mix egg whites, 1 1/2 cups granulated sugar, the cream of tartar, corn syrup and 1/3 cup water. Cook over low heat, beating with electric mixer on high speed until stiff peaks form and scraping bottom and side of saucepan occasionally. Remove from heat. Add marshmallows; beat until smooth.
• Cut cake crosswise into four 10x3 3/4-inch rectangles. Layer rectangles, spreading each with about 1 cup frosting. Spread top with remaining frosting.
• In 1-quart saucepan, heat chocolate and butter over low heat, stirring occasionally, until melted; remove from heat. Stir in powdered sugar and 5 teaspoons water until smooth. Stir in additional boiling water, 1/2 teaspoon at a time, until desired consistency. Pour glaze over cake, allowing some to drizzle down sides.