Cook the squash
Preheat the oven to 190°C/375°F.
Cut the squash in half lengthwise, remove the seeds. Place the halves on a baking sheet, cut side down. Bake about 45-50 min until soft. Alternatively, cook each halve separately in a microwave oven: Place each halve in a bowl, partially covered, then cook at high intensity about 8 min for each halve. Let the halves cool down and carve out the pulp.
Assemble the lasagna
Combine squash, white beans, canola oil, salt and pepper in a food processor and purée until smooth. Set aside.
In a large bowl, combine ricotta, spinach, half of the basil and the other seasonings. Mix well and set aside.
Using a brush, generously coat a 6-quart or larger slow cooker with olive oil.
Arrange a layer of noodles as the base of the lasagna in the slow cooker. Spread half of the squash mixture in the slow cooker. Arrange another layer noodles over the squash mixture, overlapping them slightly. Spread the ricotta mixture over the noodles and firmly pat down, then arrange a layer of noodles over the ricotta mixture, breaking into pieces to cover as much as possible. Spoon on remaining squash mixture. Finish with a layer of noodles and cover with grated mozzarella.
Put the lid on the slow cooker and cook on 'High' for 3-4 h.
Sprinkle the remaining basil on the lasagna then serve.