Pre-heat oven to 350 degrees F.
In a medium bowl, mix together cream cheese, 1 tablespoon Parmesan and spices. Spread mixture into the bottom of an oven safe 9-inch glass pie plate.
Top cream cheese mixture with 1/2 cup mozzarella and spread pizza sauce over it to edges. Sprinkle remaining 1/2 cup mozzarella, cheddar and Parmesan cheese over the sauce.
In a small saute' pan, cook the sausage over medium heat until no longer pink, breaking up into small pieces. Remove sausage from pan with slotted spoon and spread over top of cheese in pie plate.
In same pan you cooked the sausage, add the mushrooms and cook until just golden (add a little oil or butter if needed). Remove mushrooms from pan and spread over other ingredients.
Sprinkle the pepperoni, bell pepper, black olives and onions over top, adding more if desired. For a little spicier dip, sprinkle with extra red pepper flakes before baking.
Bake for 15-20 minutes or until the cheese is golden brown and bubbly.
Serve immediately with crostinis, garlic toast or sliced baugette.
Cook's note: You can assemble the pizza dip ahead of time and then refrigerate it up to 24 hours before baking. I found that serving it fresh the first day it's baked was the best and gave the freshest flavor. Personally, the flavors were not as prominent when I reheated leftovers the second day.