Just like Nonna makes!
Preheat oven to 300°F (150°C).
For SMALL & MEDIUM lasagna: cook for 1-1 ½ hours. For LARGE lasagna: cook for 2-2 ½ hours.
Cook with plastic wrap and aluminum foil on until cheese completely melts.
Remove from oven when done and let rest, covered, for approx. 1 hour before serving.