First, preheat your oven to 350°F (175°C). While the oven heats up, grab a large mixing bowl. Combine the softened cream cheese, sour cream, mayonnaise, grated Parmesan, and shredded mozzarella. Mix everything until it's smooth and creamy, ensuring there are no large lumps of cream cheese left.
Now it’s time to fold in your main ingredients. Add the well-drained chopped artichoke hearts, the thoroughly squeezed thawed spinach, and the minced garlic to the cheese mixture. Stir gently until all the ingredients are evenly distributed throughout the dip. This ensures every scoop is packed with flavor.
Give the mixture a taste and season with salt and pepper as needed. Go easy on the salt at first, as the cheeses are already salty. Transfer the dip into an oven-safe baking dish and spread it out into an even layer. Bake for 20-25 minutes, or until the dip is hot, bubbly, and beautifully golden brown on top.
Once baked, carefully remove the dish from the oven. Let the dip cool for a few minutes before serving, as it will be extremely hot. This short cooling period also allows the dip to set slightly, making it the perfect consistency for dipping. Serve it warm with your favorite crackers, bread, or veggies.