Once my sponges are baked, I leave them to cool completely and freeze them wrapped in clingfilm over night so that they are easier to decorate the next day – but this bit is completely optional of course!! Using a knife or a cheese grater, trim the sides of the cake to within a few millimetres of the cake board it’s sitting on. Add a splash of milk to the buttercream and beat for 30 seconds to loosen. Put 2 spoons of the buttercream on the top of the cake, then spread the buttercream towards the edges and down the sides with a palette knife. Scrape of any excess and discard. This layer should be very thin, almost translucent in parts. Return the cake to the fridge for 10 minutes.

Make layers. In your prepared 8-inch cake pans, layer the colors by adding a spoonful of each color into the center. The colors will spread and push out to form the rainbow layers on their own. Repeat until you have used all of the cake batter. Add second layer. Set your second cake round on top of the first and even it out until it is securely in place. Frost the sides and top in a thin ¼-inch layer. Place the cake in the fridge before covering it with fondant.

Rainbow Junior High Special Edition

Freezing: For long term storage, cover the cake tightly with plastic wrap then foil and place it in the freezer for up to a year (again dependent on any spoilable toppings and/or fillings). When ready to eat, thaw it in the fridge overnight then set it out to come to room temperature before you slice and serve. Preheat the oven to 170C/150C Fan/Gas 3. Grease 6 x 20cm/8in loose bottom sandwich cake tins (approximately 4cm/1½in deep) and line the bottoms with greaseproof paper. Dust the tins with flour, then shake out the excess. Gel food coloring is easier to work with than liquid. Particularly when coloring cake batter, icing, or frosting. It can be found in all the same locations as the clear vanilla extract listed above! Fun for everyone and perfect for any occasion, this easy marbled rainbow layer cake will be the hit of the party!! Once you have layered each sponge you need to do a crumb coat by using as little buttercream as possible around the edges to seal in the spare crumbs from the sponges! I then chill the cake for a while to firm it up before adding another layer of buttercream on top.

Color your fondant. After mixing 1 recipe of buttercream frosting and making 1 recipe of marshmallow fondant, split the fondant batch to add colors. Wrap the fondant tightly and securely until (and between)ready to use.At Rainbow High, students follow G.L.A.M (Grit, Love, Action and Moxie), and flaunting their true colors and making bold new innovations. At Shadow High, they are tired of lurking in the shadows, and want to shine. Of course, there is some major drama along the way! Divide the remaining buttercream into 6 equal portions and place in bowls. Colour the buttercream in the same way you coloured the cake batter, then place each colour into a separate piping bag.