Preheat your oven to 350°F (175°C) to ensure even baking.
Thaw the frozen spinach and drain it thoroughly to remove excess moisture.
In a mixing bowl, combine the drained spinach, chopped artichoke hearts, sour cream, Velveeta cheese, muenster cheese, and the packet of Lipton soup mix. Mix until well combined.
Spoon the mixture into a greased 2-quart baking dish, spreading it out evenly.
Place the baking dish in the preheated oven and bake for 25-30 minutes, until hot and bubbly.
Once baked, remove the dip from the oven and let it cool slightly. Serve warm with your favorite dippers.
