In a 6-qt. electric pressure cooker, combine the first 4 ingredients.
Lock lid; close pressure-release valve.
Adjust to pressure-cook on high for 3 minutes.
Let pressure release naturally for 5 minutes; quick-release any remaining pressure.
Select saute setting; adjust for medium heat.
Add the milk, cream cheese and garlic powder.
Cook and stir until cream cheese is melted, 3-5 minutes.
Stir in spinach, Parmesan cheese, sun-dried tomatoes, basil, salt and pepper.
Cook and stir until spinach is wilted. Press cancel.
Serve immediately.
Garnish with additional basil if desired.