Preheat your oven to 160°C/320°F/Gas mark 3. Melt 10g of butter in the microwave on 5 second bursts until smooth.
Thoroughly grease the pots/moulds with the melted butter. Unsalted butter is better for greasing as it has a high tolerance to heat and stops the outside of the cake burning.
Make the sponge by adding all the ingredients to a large bowl and whisk until smooth. Don’t overbeat the batter or it will become greasy.
Fill the moulds to ¾ full and bake in the oven for 30 minutes (depending on your own oven). While the cakes are baking you can mould a few shells and starfish out of fondant - you can do this by hand of use a special shell or starfish mould. Victoria used a touch of orange food colouring to make the starfish.
When the cakes are done and springy to the touch, remove them from the tray and cool completely on a wire rack.
To make the spade handles you will need a rigid chopping board or something similar and a non stick baking mat or greaseproof paper.
Melt the chocolate or Candy melts in the microwave on 10 second bursts until smooth. Use Candy melts when making these cupcakes in the summertime as they're less likely to melt than white chocolate.
You can colour the chocolate or Candy melts with powdered colouring. Victoria used yellow and blue but you can choose which you like. Don't use gel colours as it will seize the chocolate and it will be wasted.
Add the melted chocolate to a parchment paper piping bag and pipe spade shapes. Start with a small square and fill in around it before adding the handle. Make sure it's long enough to poke into the buttercream.
Remove the cakes from the moulds. Make up your buttercream and add buttercream to the outside of 4 of the cupcakes.
Roll 20g of red paste per cupcake out to 4mm thick and wrap it around the base of the cakes. Make sure the modelling paste is thick enough and then the icing will look smooth and not lumpy.
Cut a long 2cm wide strip and glue it with a brush of water around the top of the cake to give it a bucket shape. You can smooth the paste gently with the tips of your fingers to get any bumps away.
For the handle, cut a contrasting strip of paste and stick each end to the side of the bucket adding a 5mm cut circle on top of the ends.
Crush 3x Digestive biscuits in a sandwich bag by rolling the pin over it. Add the jam to the centre of the bucket cakes using a corer.
Top each cupcake with buttercream and biscuit crumb (sand). Victoria did this on a plate to contain the crumbs.
For the last remaining sandcastles, core the centres with an apple corer. Add jam and buttercream using a small sandwich bag with the corner snipped of.
Make sure you snip the corner off the bag away from the cakes so it doesn’t end up in the buttercream or cakes.
White chocolate will take a lot longer than Candy melts to set but is speeded up by popping them into the freezer. Candy melts will set a lot faster and take longer to melt in the heat.
When the handles are completely set, add them to your cupcakes by pushing them into the tops of the buttercream. Add flags to the sandcastle to decorate.