1. Bake cake as directed on the box. Let the cake completely cool.

Nutella Icing

1. Beat together butter and shortening until smooth.

2. Add Nutella and mix until smooth.
3. Slowly add 4 cups of powdered sugar and mix until smooth.
4. Add 2-3 tbsp of milk or water and mix until smooth.
5. Add fifth cup of powdered sugar and mix until smooth.
6. Add more water or milk until the right consistency.

Marshmallow Fondant

1. Place marshmallows and 2 tablespoons of water in a large microwave-safe bowl. 

2. Microwave for 30 seconds on high; stir until mixed well. Continue microwaving in 30 second intervals until they are melted and smooth.

3. Place about 5 cups of the powdered sugar on top of the melted marshmallow mixture and gently fold it into the marshmallows.
4. Grease your hands and your counter-top generously with shortening. Turn marshmallow mixture onto counter and start kneading it like you would dough.
5. Add more confectioners' sugar as needed and re-grease your hands the counter-top as needed.
6. If the marshmallow fondant is tearing easily, it is too dry; add water (about 1/2 tablespoon at a time) kneading until fondant forms a firm, smooth elastic ball that will stretch without tearing, about 8 minutes.

7. To color fondant, add a little gel color to your desired amount and knead it with your hands until it absorbs all of the color. Add more color as needed to reach the desired colored. (I use medical gloves when mixing in the color. It's very helpful while cleaning your hands after).

8. Follow directions above to assemble and decorate the cake.