In a large pan, heat olive oil. Add butternut squash and saute for 10 minutes. Add in sausage, salt, and pepper and break up sausage using a spoon. Cook, stirring frequently, until sausage is completely cooked. Add baby spinach and saute for one minute, until wilted. Remove pan from heat.
In a large bowl, mix together ricotta and mozzarella. Stir in ½ teaspoon salt and ¼ teaspoon pepper. Add in sausage mixture and mix until fully combined.
Cheese sauce: in a saucepan, melt butter. Add flour and whisk until bubbling and starting to color. Add sage, thyme, and salt, and whisk together. Slowly whisk in milk. Add mozzarella gradually, whisking continuously. Once cheese sauce is smooth and slightly thickened, remove from heat.
Boil lasagna noodles for 2 minutes less than package instructions. Drain and mix with a drizzle of olive oil.
Prep oven-proof pan by spreading a thin layer of cheese sauce on the surface. Lay out lasagna noodles and evenly spread out butternut-sausage mixture along length of noodle. Roll up noodle and tuck into pan. Repeat with the rest of lasagna noodles.
Lay out lasagna noodles and evenly spread out butternut-sausage mixture along length of noodle. Roll up noodle and tuck into pan. Repeat with the rest of lasagna noodles.
Spread cheese sausage evenly on top of the noodle roll-ups. Sprinkle with shredded Parmesan. Bake for 25 minutes until surface is slightly browned.
Remove from oven. Garnish with more Parmesan, minced parsley, and black pepper.