Preheat your oven to 375°F and lightly grease a 9-inch baking dish or small cast iron skillet. This ensures even cooking and prevents sticking while allowing golden, bubbly edges to develop beautifully throughout baking.
In a large mixing bowl, combine softened cream cheese, sour cream, and mayonnaise using an electric mixer or sturdy whisk. Beat until completely smooth and creamy, approximately 2-3 minutes, ensuring no lumps remain in the base mixture.
Fold in thawed spinach, drained artichoke hearts, mozzarella cheese, parmesan cheese, minced garlic, red pepper flakes, salt, and black pepper using a spatula. Stir gently until all ingredients distribute evenly throughout without overworking the mixture.
Squeeze fresh lemon juice over the entire cozy spinach artichoke dip mixture and fold gently one final time. The citrus brightens flavors and prevents the dip from tasting heavy or one-dimensional when served warm.
Transfer the spinach and artichoke mixture into your prepared baking dish, spreading it into an even layer. Bake for 20-25 minutes until the top turns golden brown and edges bubble slightly around the perimeter.
Remove from oven and let cool for 5 minutes before serving—it continues cooking slightly during this rest period. Serve warm with your favorite crackers, toasted bread, or fresh vegetables for optimal flavor and texture enjoyment.