
Heat the butter in a large skillet with tall sides over medium heat. Add minced garlic and saute for about 1 minute, until fragrant.
Add the spinach. Saute for 2-4 minutes, until just barely wilted. If the pan is too full to stir or you can't fit all the spinach, add what you can and cover for 1-2 minutes, which will let the spinach at the bottom wilt. Then you can start to stir in a folding motion and add more as needed.
Add the heavy cream, cream cheese, Italian seasoning, sea salt, and black pepper. Stir constantly until the cream cheese melts, then simmer for 2-3 minutes until thickened. (The sauce will thicken more as it cools from hot to warm.)
If desired, sprinkle with parmesan cheese for serving. (This is optional.)