Line a 12-hole muffin tin with 12 dark brown or black muffin cases. Heat the oven to 180C/160C fan/gas 4. Put all the ingredients in a large bowl and using a hand-held electric whisk, beat for 2-3 minutes, until fluffy.
Divide the mixture between the muffin cases, then bake for 20 -25 minutes, until risen and springy to the touch – ask an adult to help you with this bit. When the cakes are cooked, take them out of the oven and transfer to a wire rack to cool completely – ask an adult to help you with this bit too. You will need 8 of the cakes to make a full cycle of the moon. If you need to, you can trim the tops of the cakes so that they are flat.
Mix 3 tbsp of the icing sugar with enough water to make a spreadable paste and set aside. Knead the blue and black fondant icing together until the colours are almost blended together, leaving a few streaks of blue running through.
Dust a work surface with a little icing sugar and roll out the coloured icing so that it's large enough to cut out 12 x 7cm rounds. Spread a little smear of the icing sugar paste on top of each cake and stick an icing round on top.
Roll out the white icing to about 0.5cm thick. Using a small sharp knife, cut out 2 thin crescent shapes to make the waxing and waning crescent. Using a 7cm cutter, cut out 4 rounds. Cut one round in half to make the first and third quarter of the moon. Leave one round as it is to make the full moon and cut a small crescent away from the remaining 2 rounds, to make the waxing and waning gibbous moon. Using a little of the icing paste, stick each shape on to a cake. Leave one cake with nothing on – this will be the new moon. Use a star-shaped cutter to decorate the 4 cupcakes not included in the cycle with the leftover white icing.
Using a pastry brush, apply a tiny bit of water over the darker icing then sprinkle a little glitter over the top – the water helps it stick in place. Have fun arranging your cakes in a lunar cycle!