Bring a large pot of water to a boil. Heat oven to 350F.
Steam the squash until fork tender. Set aside to cool and drain well.
Into a mixing bowl add the squash, onion, garlic, ricotta, sage, 1 cup mozzarella cheese, 1/4 cup Parmigiano-Reggiano cheese, and the egg. Use a potato masher to mash the squash and combine the ingredients. Season with salt and pepper. Add additional salt to taste (season well!).
To make the bechamel, heat a small saucepan on medium heat. Add the butter and flour and whisk until smooth. Let it bubble a minute to cook the flour, then slowly whisk in the milk. Cook, stirring constantly, 3-4 minutes until just barely thickened. Set aside off the heat.
To make the Bacon Topping: Using your fingers, combine the bacon, sage, panko, and olive oil in a small bowl. Set aside.
Add a palmful of salt to the boiling water. Add the lasagna noodles and cook to al dente according to package directions. Drain and drinse with cold water until cool enough to handle.
To assemble: lay out sheets of pasta. Place a heaping 1/4 cup of the squash mixture on each and use a spoon to spread the filling along the noodle. Roll up the noodle and place in a 13x9 make dish sprayed with cooking spray. Repeat with the rest of the filling and noodles.
Top the lasagna roll-ups with the remaining 2 cups mozzarella and 1/4 cup Parmigiano-Reggiano cheeses. Pour the bechamel sauce over all the casserole. Top with bacon-panko topping.
Spray the underside of a piece of foil large enough to cover the bake dish. Cover the bake dish tightly, cooking spray-side down. Bake at 350F, covered with the foil, for 30 minutes. Remove foil and cook an additional 15-20 minutes or until just bubbly. Yields: 6 servings.