Preheat the oven to 350°F.
In a large bowl, mix softened cream cheese and sour cream until smooth using a hand mixer or stand mixer.
Add 1 cup mozzarella, parmesan, garlic, Italian seasoning, onion powder, and salt. Mix until combined.
Fold in sun-dried tomatoes, spinach, and shredded chicken.
Spread mixture into a medium baking dish or large cast iron skillet and smooth evenly.
Top with remaining ½ cup mozzarella.
Bake for 25 minutes until hot and bubbly. Broil for 1 minute until the cheese is golden.
Garnish with extra sun-dried tomatoes and fresh basil before serving.