Preheat your oven to 180°C/160°C
fan and line a 13x9 inch Swiss roll tin with greaseproof baking paper.
Add the eggs, caster sugar and
vanilla to a large mixing bowl and whisk on a medium-high setting for 10 mins,
until the mixture has thickened.
Divide the mixture into 5
separate bowls and colour each a different colour. Fold the colours in using a
metal spoon, being careful not to knock out too much of the air.
Sift 35g of flour into each bowl
and gently fold in.
Mix 2 tsp of the melted butter
into each bowl.
Add the mixtures into 5 separate
piping bags and cut a 1cm opening at the end.
Pipe diagonal lines of cake
mixture from one corner of the baking tray to the other.
Tap the tray on your work surface
a couple of times and bake in the oven for 8-10 mins, the sponge should be firm
to the touch.
Leaving the sponge on the baking
paper, slide it onto a damp tea towel and peel the baking paper from the sides.
Roll up the sponge widthways in
the tea towel and leave to fully cool.
Pour the cream and icing sugar
into a mixing bowl and whisk until the cream just starts to hold its shape.
Fold in the sprinkles.
Gently unroll the cooled sponge
and spread the cream over it, leaving a 2 cm border.
Roll the sponge back up and dust
with icing sugar when ready to serve.
