Preheat your oven to 400°F (205°C). Peel the butternut squash, cut ends off, halve lengthwise, scoop out seeds, and cut into 1-inch cubes. Place cubes on baking sheets, drizzle with olive oil, salt, and pepper. Roast for 25-30 minutes until tender and caramelized.

Transfer roasted squash to a food processor. Add nutmeg and optional maple syrup. Process until smooth. Set aside.

In a medium saucepan, melt butter over medium heat. Add flour, whisk constantly for 2 minutes to form roux. Gradually add warmed milk, whisking to prevent lumps. Add bay leaves, simmer, stirring frequently for 10-12 minutes until thickened. Remove bay leaves, stir in nutmeg, salt, and white pepper. Cover surface with plastic wrap and set aside.

Combine ricotta, eggs, chopped sage, parsley, half cup Parmesan, salt, and pepper in a bowl until smooth. Set aside.

Preheat oven to 375°F (190°C). Grease a 9x13 inch baking dish. Spread ½ cup béchamel sauce on bottom. Layer 3 lasagna noodles, 1½ cups squash puree, one-third ricotta mixture, ½ cup mozzarella, and ½ cup béchamel sauce.

Repeat layers three more times: noodles, squash puree, ricotta, mozzarella, and béchamel. Finish with noodles topped with remaining béchamel, mozzarella, and ¼ cup Parmesan.

Cover with foil tented to avoid touching cheese. Bake 40 minutes. Remove foil, bake 15-20 minutes more until cheese bubbles and browns. Optional broil 1-2 minutes for extra browning.

Let lasagna rest 15 minutes before cutting. Garnish with fresh sage leaves and serve warm.