Mississippi Mud Cake

PreparationFor Cake: Preheat oven to 350°F. Line two 9-inch square cake pans with 2-inch-high sides with foil, extending foil over sides. Butter and flour foil. Using electric mixer, cream butter and both sugars in large bowl until fluffy. Beat in melted chocolate, cream and vanilla. Add eggs 1 at a time, beating well after each addition. Sift flour, cocoa, baking soda and salt into medium bowl. Stir dry ingredients into batter, which will be very thick. Divide batter between prepared pans; spread evenly. Bake until tester inserted into centers comes out clean, about 20 minutes. Remove from oven. Sprinkle 1 1/2 cups marshmallows and 1 cup pecans over each cake. Bake just until marshmallows begin to melt, about 6 minutes. Transfer to racks. Cool cakes completely in pans. For Frosting: Combine sugar and cream in heavy medium saucepan. Stir over medium heat until sugar dissolves. Cook without stirring until candy thermometer registers 220°F., about 8 minutes. Remove from heat and whisk in remaining ingredients. Whisk until all chocolate melts and frosting is smooth. Refrigerate frosting until spreadable, about 1 hour 15 minutes. Using foil as aid, lift cakes from pans. Remove foil. Place 1 cake layer on plate, marshmallow side up. Spread 1 1/2 cups frosting over. Top with second cake layer, marshmallow side up. Spread remaining frosting in waves on sides (not top) of cake. (Can be prepared 1 day ahead. Cover with cake dome and chill. Bring to room temperature before serving.)

PreparationFor Cake: Preheat oven to 350°F. Line two 9-inch square cake pans with 2-inch-high sides with foil, extending foil over sides. Butter and flour foil. Using electric mixer, cream butter and both sugars in large bowl until fluffy. Beat in melted chocolate, cream and vanilla. Add eggs 1 at a time, beating well after each addition. Sift flour, cocoa, baking soda and salt into medium bowl. Stir dry ingredients into batter, which will be very thick. Divide batter between prepared pans; spread evenly. Bake until tester inserted into centers comes out clean, about 20 minutes. Remove from oven. Sprinkle 1 1/2 cups marshmallows and 1 cup pecans over each cake. Bake just until marshmallows begin to melt, about 6 minutes. Transfer to racks. Cool cakes completely in pans. For Frosting: Combine sugar and cream in heavy medium saucepan. Stir over medium heat until sugar dissolves. Cook without stirring until candy thermometer registers 220°F., about 8 minutes. Remove from heat and whisk in remaining ingredients. Whisk until all chocolate melts and frosting is smooth. Refrigerate frosting until spreadable, about 1 hour 15 minutes. Using foil as aid, lift cakes from pans. Remove foil. Place 1 cake layer on plate, marshmallow side up. Spread 1 1/2 cups frosting over. Top with second cake layer, marshmallow side up. Spread remaining frosting in waves on sides (not top) of cake. (Can be prepared 1 day ahead. Cover with cake dome and chill. Bring to room temperature before serving.)