01 - Set the oven to 375°F (190°C) to prepare for baking.
02 - In a large mixing bowl, blend cream cheese, sour cream, and mayonnaise until smooth and creamy.
03 - Incorporate mozzarella, parmesan, and cheddar cheeses, reserving 1/4 cup mozzarella and 2 tablespoons parmesan for topping.
04 - Fold in the well-drained spinach, chopped artichoke hearts, and minced garlic. Season with salt, black pepper, and crushed red pepper flakes if desired. Stir thoroughly.
05 - Transfer the mixture into a 1.5-quart baking dish, smooth the surface, and sprinkle reserved cheeses evenly on top.
06 - Bake for 20 to 25 minutes until the mixture is bubbly and the top achieves a golden-brown crust.
07 - Allow to cool for 5 minutes before serving warm alongside tortilla chips.