Turn the Instant Pot on Saute mode and add the butter to the pot and stir until melted. Add the rice and stir to coat. Then, add the sugar, vanilla, water, milk, and cinnamon to the pot and mix to combine.

Place the lid on the Instant Pot and set the valve to Sealing. Turn on the Instant Pot to Manual mode and set the time for 10 minutes.

When the time is up, do a quick release by turning the valve to Venting. While the steam is releasing, whisk together the egg and whipping cream in a small bowl.

When all the steam is released, carefully open the lid and scoop about a cup of the hot mixture into the bowl with the egg/cream mixture while mixing quickly. Add the contents of the bowl back to the Instant Pot and turn it on the Saute mode once again and bring the mixture to a boil for 60-90 seconds (while stirring constantly) to cook the egg.

Serve immediately with ice cream or whipped cream. Enjoy!