01 - Preheat the oven to 375°F. Lightly grease an 8-inch square baking dish or equivalent.
02 - In a large mixing bowl, beat together cream cheese, sour cream, and mayonnaise until smooth and creamy.
03 - Add mozzarella, Parmesan, spinach, artichokes, garlic, salt, black pepper, red pepper flakes if desired, and onion powder. Stir thoroughly to combine evenly.
04 - Spread the mixture evenly into the prepared baking dish. Bake for 20 to 25 minutes until hot, bubbly, and lightly golden on top.
05 - Serve immediately with tortilla chips, sliced baguette, crackers, or fresh vegetable crudités.