Preheat your oven to 350°F (175°C).
Using a rolling pin, flatten each slice of sandwich bread to about half its thickness.
Gently press each flattened slice into the muffin tin, covering the sides and bottom to create a cup shape.
Place the muffin tin in the preheated oven and bake for about 10-12 minutes until lightly golden and crispy.
In a large mixing bowl, combine cream cheese, mayonnaise, sour cream, mozzarella, Parmesan, garlic salt, spinach, and artichokes. Mix until creamy.
Spoon the mixture into each bread cup, packing slightly for a hearty serving.
Return the muffin tin to the oven and bake for an additional 15-20 minutes, or until bubbly and golden brown.
Allow to cool for a few minutes before removing from the muffin tin. Serve warm.
