01 - Preheat your oven to 375°F.
02 - In a large mixing bowl, combine softened cream cheese, sour cream, and mayonnaise. Mix until smooth.
03 - Stir in mozzarella, Parmesan, spinach, artichoke hearts, garlic, salt, black pepper, and red pepper flakes if using.
04 - Transfer the mixture to a medium baking dish and spread evenly.
05 - Bake for 25 minutes, or until the dip is bubbly and lightly golden on top.
06 - Serve warm with tortilla chips, sliced baguette, or fresh vegetables.