Preheat the oven to 375 degrees F.
In a large mixing bowl, mix together the 16 ounces of cream cheese, 1 cup of shredded mozzarella cheese, 1/4 cup of shredded Parmesan cheese, 2 minced cloves of garlic, and 1/2 cup of frozen chopped spinach.
Transfer the mixture to a 9-inch round casserole dish and spread the mixture out until it is even. You can also use a 9-inch cast iron skillet, really any 2 1/2 quart casserole, or even a 9-inch pie plate.
Add 1 cup of pizza sauce and spread the sauce evenly over the top of the cream cheese mixture.
Add the remaining 1/2 cup of mozzarella cheese, 1/2 cup cheddar cheese, 4 ounces of sliced mushrooms, and 2 ounces of sliced California olives.
Place the dish in the oven and bake for 30 minutes. It is done when the cheese has melted and the dish is bubbly around the edges.
Enjoy!