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