Preheat oven to 400°F.
Heat a dutch oven to medium, add olive oil then onions and sauté 7 minutes then add garlic and sauté until soft and translucent, approximately 2 more minutes.
Add tomatoes and stir, then add in dried parsley, oregano and red pepper flakes and bring the mixture to a boil. Reduce heat and simmer uncovered for 1 hour until sauce has thickened. Using a wooden spoon break up any large tomatoes.
While the sauce is simmering cook the spaghetti squash. First cut the squash in half - be very careful. Start in the middle of one side with the point the chef knife and slide down to the non stem end and then around the bottom and up to the top. If the squash is rolling around then put a tea towel under it on the cutting board to hold it in place.
Scoop out the seeds, discard and drizzle with a little olive oil and a sprinkle of S&P. Place cut side down on a baking sheet and bake for 30-45 minutes depending on the size. You will know it is done if a fork can easily piece through the side. Set aside to cool a bit.
After the sauce has finished simmering remove from heat and add most of the basil (reserve a bit for garnish before serving), 1 tsp salt and 1/4 black pepper. Taste and add more seasoning if desired.
Once the squash is cool take a fork and drag it across the middle and add the spaghetti strands to your sauce. You should have appoximately 2 cups. If there is more you may want to save it for another use.
Heat ricotta in a small saucepan until warm, stir in 2 cups of mozzarella and continue to stir until melted. Remove from heat and add 1/4 tsp salt and a sprinkle of pepper.
In a rectangular baking dish start with a tomato sauce layer (1/3 of the mixture), then a noodle sheet, half the ricotta, noodle sheet, another layer of tomato sauce, noodle sheet, remaining ricotta mixture, last noodle layer and top with your remaining tomato sauce. Pour about a 1/4 cup of water over the top of the lasagna (maybe a little more if the sauce is thick) and sprinkle with parmesan cheese.
Lasagna can be made up to one day ahead of time and stored in the refrigerator until 1 hour before dinner.
Bake at 350 degrees for 30 minutes until bubbling or longer if lasagna has been refrigerated.
Remove from the oven and put temperature to broil. Sprinkle with remaining 1/2 cup mozzerella cheese and broil for 3-5 minutes. Let stand 10 minutes before serving and top with reserved basil.