Step 1
Preheat the oven to 375 degrees F (190 degrees C).
Step 2
Toss butternut squash olive oil sage salt and black pepper together in a bowl. Transfer to a baking sheet.
Step 3
Bake in the preheated oven until soft about 20 minutes.
Step 4
Meanwhile heat marinara sauce in a saucepan over low heat until warm about 5 minutes. Heat 1 tablespoon olive oil a saute pan over medium heat; cook and stir onion and 2 garlic cloves until golden brown 5 to 7 minutes. Add onion mixture to marinara in the saucepan and remove from heat.
Step 5
Heat 1 tablespoon olive oil in the saute pan over medium heat. Add spinach and cook until wilted about 3 minutes. Transfer spinach to a plate lined with paper towels to absorb the moisture; move spinach to a bowl. Add turkey remaining garlic Italian seasoning and crushed red pepper to the pan. Cook until brown 5 to 7 minutes. Season with salt and black pepper and mix into the bowl with the spinach.
Step 6
Remove butternut squash from the oven and leave oven on.
Step 7
Bring a large pot of lightly salted water to a boil. Cook lasagna noodles in the boiling water stirring occasionally until tender yet firm to the bite about 8 minutes. Drain and lay noodles separately on a plate to keep from sticking.
Step 8
Combine cooked butternut squash ricotta cheese and eggs together in a bowl until smooth.
Step 9
Coat the bottom of a 9x13-inch baking pan with a thin layer of marinara sauce. Layer 3 lasagna noodles over the marinara followed by ricotta mixture and ground turkey. Repeat marinara noodles ricotta mixture and turkey 2 more times. Top with mozzarella cheese and Parmesan cheese.
Step 9
Bake in the hot oven for about 45 minutes; let cool 10 minutes before cutting.