01 -
Heat a skillet or griddle over medium heat until hot.
02 -
Spread softened butter evenly on one side of each slice of bread.
03 -
In a small bowl, combine ricotta, shredded mozzarella, and grated Parmesan cheese, mixing until homogeneous.
04 -
Place two buttered bread slices on the skillet, buttered side down. Spread the cheese blend evenly over the bread, then top with chopped sun-dried tomatoes and fresh spinach leaves. Cover with the remaining slices, buttered side up.
05 -
Grill each sandwich for 3 to 4 minutes per side until the bread is golden brown and the cheese is fully melted.
06 -
Remove from skillet and let rest briefly, then cut sandwiches in half and serve warm.