Preheat the oven to 375°.

Place the pepperoni on a paper towel lined plate. Microwave on high for 45 seconds. Blot the tops of pepperoni with a paper towel to remove excess oil. Set aside.

Stir to combine the cream cheese, 1/2 cup parmesan, and Italian seasoning in a medium mixing bowl. Spread the mixture in an even layer in a 9-inch deep dish pie plate.

Add 1/2 cup marinara and spread evenly over the cheese mixture. Sprinkle with 1 cup mozzarella, 1/2 cup parmesan, and 2 tablespoons each of pepperoni, black olives, bell pepper, and red onion. Repeat with the remaining marinara, mozzarella, parmesan, pepperoni, olives, bell pepper, and red onion.

Bake until the cheese is bubbling and beginning to brown, about 30 minutes.

Increase the oven to broil and bake 2 minutes more. Let cool for 10 to 15 minutes before serving. Serve with toasted baguette slices.