Preheat your oven to 375°F (190°C) and lightly grease a 1-quart baking dish or a 9-inch pie plate with non-stick cooking spray.
In a large mixing bowl, combine the softened cream cheese, ricotta cheese, 1/2 cup of the mozzarella cheese, Parmesan cheese, beaten egg, garlic powder, oregano, salt, and pepper. Mix with a hand mixer or a wooden spoon until all ingredients are fully incorporated and the mixture is smooth.
Spread the cheese mixture evenly into the bottom of the prepared baking dish using a spatula.
Pour the marinara sauce over the cheese layer and use the back of a spoon to spread it into a smooth, even layer that covers the cheese completely.
Sprinkle the remaining 1/2 cup of shredded mozzarella cheese evenly over the top of the marinara sauce.
Bake for 20-25 minutes, or until the edges are bubbling and the top layer of cheese is golden brown and melted.
Carefully remove the dip from the oven and let it rest for 5 minutes to set slightly. Garnish with the fresh basil before serving warm with tortilla chips or sliced baguette.