01 - Preheat your oven to 375°F.
02 - In a large mixing bowl, combine cream cheese, sour cream, and mayonnaise. Mix until smooth and creamy.
03 - Stir in the Parmesan, mozzarella, garlic, salt, black pepper, and red pepper flakes until well combined.
04 - Fold in the spinach and chopped artichoke hearts until evenly distributed throughout the mixture.
05 - Transfer the mixture to a 1-quart baking dish and smooth the top evenly.
06 - Bake for 25 minutes, or until the dip is hot and bubbly with a lightly golden top.
07 - Serve warm with tortilla chips, pita bread, or vegetable crudités.