Add dry pasta, chicken broth, and salt to Instant Pot. If you have one, I recommend using a nonstick insert.
Lock lid, move vent to Sealing, and set to pressure cook on High for 2 minutes. Let pressure release naturally for 5 minutes, then vent any remaining pressure. Press Cancel to turn off warming function.
Stir vigorously to separate pasta grains, about twenty to thirty times. Add butter and stir until melted. Stir in beaten eggs and combine thoroughly. Add spinach and stir to submerge leaves.
Replace lid (no need to lock it in place) and let rest for 10 minutes. This is the most important step as it will allow the eggs and spinach to cook and the pasta to absorb any remaining moisture.
Remove lid, give it another few good stirs, and serve. Top with grated parmesan cheese or red pepper flakes if desired.
