01 - Preheat oven to 375°F.
02 - In a medium skillet over medium heat, add fresh spinach and cook until wilted, about 2-3 minutes. Remove from heat and roughly chop. If using frozen spinach, ensure it is thoroughly thawed and squeezed dry.
03 - In a large mixing bowl, combine cream cheese, sour cream, and mayonnaise. Beat until smooth and fully incorporated.
04 - Stir in mozzarella, Parmesan, garlic, chopped artichokes, and spinach. Season with salt, black pepper, and red pepper flakes if using. Mix until well combined.
05 - Transfer the mixture to a 1-quart baking dish and smooth the top evenly.
06 - Bake for 20-25 minutes, or until hot and bubbling, and the top is lightly golden brown.
07 - Let cool for 5 minutes before serving. Serve warm with tortilla chips, sliced baguette, or vegetable sticks.