01 - Preheat oven to 350°F. Lightly grease an 8-inch square baking dish with cooking spray or butter.
02 - In a large mixing bowl, combine softened cream cheese, sour cream, and mayonnaise. Beat with a hand mixer or whisk until completely smooth and no lumps remain.
03 - Add mozzarella, Parmesan, drained spinach, chopped artichokes, 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, smoothing the top with a spatula.
05 - Bake for 25 minutes until the dip is bubbling around the edges and the top develops a light golden-brown color.
06 - Remove from oven and let stand for 5 minutes to allow the dip to set slightly. Serve warm accompanied by tortilla chips for dipping.