Add 2 pounds chicken breasts, 2 cups heavy whipping cream, 4 cups chicken broth, 4 tablespoons butter, ½ teaspoon garlic powder, and 1 tablespoon Cajun seasoning to an Instant Pot (at least 6-quart).
Seal and cook on high pressure for 17 minutes, then perform a quick release. Ensure the chicken reaches 165°F internally.
Remove the chicken and shred or dice into large pieces.
Whisk the sauce remaining in the Instant Pot.
Return the chicken to the pot and stir in 1 pound uncooked penne pasta.
Seal and cook on high pressure for 3 minutes, then perform a quick release.
Stir in 8 oz grated Parmesan cheese and allow the heat to melt the cheese (do not turn the Instant Pot back on).
Serve warm and enjoy.
Notes
If you are sensitive to spice, reduce the cajun seasoning in half in this recipe. Refrigerate the leftovers in an airtight container for up to 5 days. When the pasta is cooking, make sure to release the pressure immediately to prevent the pasta was getting soggy in the instant pot.