Bake a rainbow cake
A rainbow cake hides its full effect until the first slice reveals distinct coloured layers. The project combines ordinary sponge-making with organisation: equal portions, consistent baking and a filling firm enough to hold a tall stack. Six slim red, orange, yellow, green, blue and violet layers are classic, but any clear sequence that survives cutting can deliver the moment. Use one tested layer-cake recipe written for your tin size and calculate the total batter before starting. Gel colouring usually adds strong colour without the extra liquid of some alternatives; check its ingredients and suitability for the people eating. Weigh the mixed batter into equal bowls, colour progressively with clean utensils and label tins or parchment so the order remains clear. Bake equal layers under the same conditions, rotating only if the recipe and oven require it, and check doneness without drying thin sponges. Cool completely on racks, level only when firm and chill delicate layers before assembly. Build on a stable board with measured filling, checking the sides after each addition. A light crumb coat can contain crumbs before the final icing. Keep raw ingredients away from ready-to-eat decoration and provide accurate allergen information. Store according to the most perishable filling and use dowels or professional transport advice for an unusually tall cake. Completion is baking, stacking and slicing one stable cake with a recognisable rainbow insideānot producing perfectly identical stripes, using excessive dye to rescue overbrowned layers or serving a leaning structure whose dramatic height makes it unsafe to move.