Use the smoke pre-set on your pellet grill to preheat to 225˚ F (107˚ C).
Slice your eggplant lengthwise, then oil and season with salt, pepper and garlic powder. Place on grill and smoke for approximately 1 hour.
While your eggplant cooks, you can prep your sauce and cheese filling. For the sauce, sautee onion and mushrooms in oil, garlic and oregano, then add your tomato sauce and simmer.
For the cheese filling, mix your ricotta, 1/2 cup of parmesan, eggs and spinach together in a large bowl.
Remove your eggplant from the grill, and turn up the temperature to 350˚F (176˚C). Assemble your lasagna in a large oven-safe dish, layering noodles, eggplant, sauce and cheese filling. Finish the top with your shredded mozzarella and the last 1/4 cup of parmesan. Place on the grill and bake for roughly an hour until the noodles have softened and the cheese is fully melted.