Place the spaghetti noodles in the inner pot of instant pot and break the noodles so they will fit into the pot. Lay the noodles in a criss cross pattern for better results, so the noodles won't stick much.

Add the salt, garlic powder and water to the instant pot.

Also place the butter on top, then close the instant pot with lid in sealing position and cook in high pressure for 3 minutes.

Once the cooking is done and the instant pot beeps, press cancel button and wait for a natural pressure release for 12 minutes.

Once the natural pressure release is done for 12 minutes, carefully do a gradual manual pressure release to release any remaining pressure.

Once the pressure is all released, carefully open the lid.

Add heavy cream and parmesan cheese also to the pot, mix to combine with the noodles.

For best results, wait for a few minutes so the noodles will absorb all the sauce (for about 5 to 6 minutes keeping the pot closed).

Transfer to serving plates, top with dried parseley or add in black pepper powder if desired, and serve the alfredo spaghetti while it is still warm for best results.