I used a plain white vanilla cake recipe and split it into 6 roughly equal bowls. Then I tinted each bowl with a different colour of food dye - generally dye bakes darker but mine stayed really pale!
Fill the muffin tins by pouring each differently-dyed batter in one at a time, then following in Rainbow order. Come on people, it's Roy G. Biv here telling you to remember your elementary science lessons... How could you forget!
Bake off your lucky charms following your cake recipe, cool, and ice however you like it!
Feel free to serve your cupcakes in miniature cake slices so your regular-sized friends can feel like giants!