Preheat oven to 350°.
Grease a 9x13” glass baking dish. (Or spray with cooking spray).
Microwave spinach according to package directions.
Drain, squeeze out any excess water.
Set aside to cool.
In a skillet over medium heat, cook bacon until crisp.
Remove from skillet and drain on paper towels.
Reserve drippings and sauté onions in drippings until translucent.
Remove onion from skillet, and transfer to a large mixing bowl.
Add spinach, 4 pieces of bacon broken into tiny pieces, melted butter, artichokes, 1 cup Parmesan cheese, sour cream, pimientos, nutmeg, salt and pepper.
Stir to combine and pour into the prepared casserole dish.
Sprinkle 1 more cup Parmesan cheese over the top.
Sprinkle remaining two pieces of bacon broken up into tiny pieces over top of cheese.
Bake for 35 to 40 minutes at 350° until top is golden.
Add remaining 1 cup of parmesan cheese and bake an additional 3-5 minutes or until cheese melts.
Serve with crackers, chips or other dippers.