Preheat the oven to 375°F (190°C).
Heat olive oil in a large skillet over medium heat.
Add diced onion and cook until softened.
Add minced garlic and cook for about 30 seconds.
Add ground turkey to the skillet.
Cook until browned, breaking the meat apart with a spatula.
Season with salt, pepper, and Italian seasoning.
Reduce heat to low.
Stir in cream cheese and allow it to melt into the turkey.
Add sour cream and mix until smooth and creamy.
Stir in shredded mozzarella and cheddar cheese.
Transfer the mixture into a greased casserole dish.
Spread evenly with a spatula.
Sprinkle the remaining mozzarella cheese over the top.
Bake for about 20 minutes until bubbly and golden.
Garnish with chopped parsley before serving.