Add the cellentani pasta to the inner pot and add enough water to just cover the noodles. Add the salt and stir to combine.
Pressure Cook on High for 3 Minutes. Quickly release the pressure once the time has completed. Strain the pasta into a colander.
Preheat the empty and cleaned inner pot for 20 Minutes on Sauté, Normal/Medium.
Add the butter and stir until melted. Add the frozen corn and sauté for 10 Minutes, until the corn has defrosted and is golden brown in color.
Sprinkle the flour over the corn and stir to combine. Add the milk and bring to a boil until slightly thickened. The sauce should resemble the consistency of a loose pancake batter.
Whisk in the parmesan, ricotta, and shredded mozzarella until melted. Pour in the cooked pasta and stir to combine.
Press Cancel on the unit and add more milk to reach desired sauce consistency. Add salt to taste. Serve pasta warm with minced parsley.