01 - Set the oven temperature to 350°F.
02 - In a large mixing bowl, beat together the cream cheese, sour cream, and mayonnaise until smooth.
03 - Stir in the chopped artichoke hearts, thawed spinach, minced garlic, mozzarella, and half of the Parmesan cheese.
04 - Add salt, black pepper, and crushed red pepper flakes if desired; mix thoroughly to combine.
05 - Transfer the mixture into a 1-quart baking dish, smooth the top, and sprinkle remaining Parmesan cheese over it.
06 - Bake for 20 to 25 minutes until the mixture is bubbly and the top is lightly golden.
07 - Serve immediately with tortilla chips, sliced baguette, or fresh vegetable sticks.