Preheat preheat your oven to 180C(160C for fan assisted ovens) Gas Mark 4.Grease two 20cm cake tins.
Mix the cake mix, oil, water and eggs together and whisk (by hand or electric mixer) for 2-3 minutes until smooth and creamy.
Pour the cake mixture evenly into your greased square cake tins.
Bake in the centre of the oven for 31-36 minutes, or until a rounded knife inserted into the centre of the cake comes out clean, then cool on a wire rack.
Cut out your superhero using a serrated knife (as shown in diagram) and place on serving plate or foil-covered tray.
Mix 1 tub of Vanilla Style Icing using the blue food colouring and divide the second tub into 3 separate small bowls; add pink food colouring to 1 bowl, yellow to the second bowl and red to the third bowl.
Spread a thin layer of blue frosting on the body and arms to seal in the crumbs. Then spread a thin layer of pink frosting on to the head and refrigerate for 30 minutes to allow the frosting to set.Spread the remaining pink icing on the head. With 1/2 cup of the blue icing, create a mask on the face. Spread remaining blue icing to cover the body and arms. Generously spread yellow icing on top of the head for hair and at the bottom of the cake to make a belt. In centre of the body, spread the red icing in an oval shape. Create a lightning bolt with the yellow icing on the red oval.
Add sweets on the mask to make eyes and use decorating gel to pipe nose and mouth, and to outline the oval, belt and belt buckle. Crumple fruit snacks or red material and place next to the body to look like a cape.