Preheat the oven to 375 degrees F (190 degrees C).

Fill a large pot with lightly salted water and bring to a rolling boil. Stir in lasagna and return to a boil. Cook uncovered, stirring occasionally, until tender yet firm to the bite, about 8 minutes.

While the noodles are cooking, combine crumbles, sausage, meatballs, squash, carrots, onion, mushrooms, oil, garlic powder, pepper, oregano, thyme, and fennel in a large bowl; stir until mixed. Combine marinara sauce and diced tomatoes in a second bowl.

Drain pasta. Grease a 9x13-inch baking dish with olive oil. Spread a thin layer of sauce on the bottom. Cover the sauce with 1 layer of lasagna noodles, a thin layer of sauce, 1/2 of the filling, and about 4 tablespoons sauce; repeat layers once more. Add the last layer of lasagna noodles and spoon a generous amount of sauce on top. Cover the dish with aluminum foil.

Bake in the preheated oven until fully cooked, 30 to 40 minutes.