Preheat oven to 180ºC . Grease and flour 33 cm x 23 cm pan.
*CAKE*
Combine cake mix, pudding mix, eggs, water and oil in large bowl. Beat at medium speed with electric mixer for 2 minutes. Stir in 1 cup miniature chocolate chips. Pour into pan. Bake at 180ºC for 40-45 minutes or until toothpick inserted in center comes out clean.
*TOPPING*
Immediately arrange marshmallows evenly over hot cake. Place frosting in microwave-safe bowl. microwave at HIGH for 25-30 seconds. Stir until smooth. Drizzle evenly over marshmallows and cake. Sprinkle with 2 tablespoons chocolate chips. Cool completely.
*TIP*
For ease in cutting, use knife with thin, sharp blade. Clean knife with paper towl after each slice.