Preheat your oven to 375°F (190°C). This ensures it's hot and ready to bake your dip to perfection.

Thaw the frozen chopped spinach by leaving it in the refrigerator overnight. Once thawed, place the spinach in a clean kitchen towel and squeeze out as much excess water as possible. Excess liquid can make your dip too runny, so this step is crucial. If you're using fresh spinach, just wash and chop!

In a large mixing bowl, combine the sour cream, mayonnaise, Parmesan cheese, shredded mozzarella cheese, and room-temperature cream cheese. Stir until the mixture is well blended and smooth.

Add the drained and chopped artichoke hearts and the prepared spinach to the cheese mixture. Stir in the minced garlic (or garlic powder), lemon juice, red pepper flakes, garlic salt, salt, and pepper. Mix everything until well incorporated.

Spoon the mixture into an oven-safe baking dish. A 9-inch pie dish or an 8x8-inch square baking dish works well for this recipe. I like using my cast iron! Smooth the top with a spatula to ensure even baking.

Place the baking dish in the preheated oven and bake for 25-30 minutes, or until the dip is hot and bubbly and the top is lightly golden. If you prefer a browner top, you can broil the dip for an additional 2-3 minutes, watching closely to prevent burning.

Carefully remove the dish from the oven and let it cool for a few minutes before serving. Transfer the hot dip to a serving bowl and surround it with your favorite dippers like crackers, tortilla chips, pita chips, and fresh vegetables.