In a food processor/blender (you can also do this by hand), combine ricotta, parmesan cheese, Italian seasoning, garlic, and olive oil. Process until smooth and creamy.
Transfer the mixture to a cheese baker or a baking dish.
Add the shredded mozzarella, then top with the cooked sausage, pepperoni, and pepperoncini.
Cover with the lid (or foil) and bake for 15 minutes.
Remove the lid/foil and broil just for a few seconds to crisp up the pepperoni (*optional)