Add rice, sugar, salt, milk, and cinnamon stick to the Instant Pot.
Secure the lid, turn the pressure release valve to the SEALING position.
Turn the machine on and press PRESSURE COOK (it will default to HIGH PRESSURE)
Set time to 10 minutes with the + BUTTON
When the beeper goes off, do nothing for 10 minutes, then release the pressure by setting the pressure release valve to the VENTING position.
After the pressure has released, open the pot and give everything a good stir. Remove the cinnamon stick. Note: it will look thin and lumpy at this point but don't panic!
Stir in the egg yolk, cream, and vanilla mixture. Stir for a couple of minutes so the egg yolks cook and the pudding thickens. Note: the pudding will still seem a little loose ~ this is good. It will continue to thicken as it cools.
Spoon into small serving cups or glasses.
Serve the pudding right away, or chill it (I like to enjoy it warm!) The pudding will thicken considerably as it chills. Top with whipped cream and a dash of cinnamon if you like.
If you would like to keep the pudding warm, press the KEEP WARM button and replace the cover. You can keep the pudding warm up to 2 hours. Be sure to give it a good stir before serving. Note: my machine's KEEP WARM setting has 3 levels, and I used the middle one, which reads NORMAL.
Be sure to use Arborio rice for this recipe. I have not tested it with other types of rice and you may not have the same results.
The cinnamon stick gives the pudding a very gentle hint of cinnamon. If you don't have one, use 1/2 teaspoon of ground cinnamon, or more to taste.
If you don't have vanilla bean paste, add 1 1/2 teaspoons of vanilla extract.