Preheat oven to 375°F (190°C).
In a medium bowl, beat the Greek yogurt and Neufchâtel cheese until thoroughly combined and smooth.
Stir in the squeezed spinach, chopped artichokes, minced garlic, onion powder, red pepper flakes, salt, and black pepper.
Add the Parmesan cheese and 0.25 cup of the mozzarella cheese to the mixture; stir until incorporated.
Transfer the mixture into a 1-quart oven-safe baking dish and spread evenly.
Sprinkle the remaining 0.25 cup of mozzarella cheese over the top.
Bake for 20 to 25 minutes or until the dip is heated through and the cheese on top is melted and lightly golden.
Serve immediately with fresh vegetables or whole-grain pita chips.