Preheat a griddle pan on your stove over medium heat.

Spread butter on one side of each slice of bread.

Spread 2-3 tbsp of spinach artichoke dip on the inside of 4 of the bread slices.

Place these four slices butter side down on the griddle.

Sprinkle 1 tbsp of mozzarella cheese on top of the spinach dip on each sandwich.

Top the sandwiches with the remaining 4 slices of bread, butter side up.

Cook for 2-4 minutes or until the bottom of the bread is toasted and golden brown, checking about every minute.

Flip over the sandwich and cook the second side for 2-3 minutes or until toasted and golden brown.

Serve immediately. Best served with this Creamy Tomato Basil Soup