01 - Preheat the oven to 350°F. Lightly grease an 8-inch square baking dish with cooking spray or a thin layer of butter.
02 - In a large mixing bowl, combine softened cream cheese, sour cream, and mayonnaise. Beat with a spoon or electric mixer until completely smooth and no lumps remain.
03 - Add shredded mozzarella, grated Parmesan, drained spinach, chopped artichoke hearts, minced garlic, salt, black pepper, and red pepper flakes. Fold everything together until evenly distributed throughout the creamy base.
04 - Spread the mixture evenly into the prepared baking dish, using a spatula to create a smooth, level surface.
05 - Bake for 25 minutes until the cheese is fully melted, the dip is bubbling around the edges, and the top develops a light golden color.
06 - Remove from the oven and let the dip rest for 5 minutes. This allows the cheese to set slightly for easier scooping.
07 - Serve immediately with tortilla chips while still warm and creamy.