Spray the bundt tin with cooking spray and set aside.

Make cake mix according to packet instructions and separate batter into four bowls.

Add a different food colouring into each bowl of batter and mix until well combined.

Then layer the cake batter in the cake tin starting with the red batter, followed by the orange batter, then blue then purple. Do not mix the layers.

Cover the bundt hole with folded kitchen paper and the wrap the cake pan in aluminum foil.

Place cake pan on trivet.

Add 350 ml (1.5 cups) of water into the Instant Pot insert and add in the trivet.

Lock the lid, set to sealing, select manual (high pressure) and set time for 40 mins.

Let cook until done and allow NPR (Natural Pressure Release) for 10 mins, then QR (Quick Release).

Remove pan from Instant Pot, remove the foil and let cool in the pan for 10 mins. Then carefully invert, transfer to a wire cooling rack and let cool.

Add the sugar in a bowl and add 2 tbsp of water and mix until the mix is smooth. Add more water if you want it thinner.

Drizzle the icing over the cake and add sprinkles liberally.