1. Preheat oven to 375 degrees F. Line a rimmed baking sheet with foil and spray with vegetable cooking spray. Line a plate with paper towels and set aside.
2. Cut squash in half lengthwise and remove and discard seeds. Place cut-side down on prepared baking sheet. Bake squash until there is a slight give when you press into the skin, about 45 to 50 minutes. Remove from oven and turn over to cool, about 15 to 20 minutes.
3. When cool enough to handle, use a fork to carefully remove flesh in long strands and place in a large bowl. Cool flesh to room temperature, about 30 minutes, then add cheddar cheese, thyme, Italian seasoning, salt, and black pepper. Stir to combine.
4. While squash cools, heat oil in a large skillet over medium-high heat. Remove sausages from their casings and add to pan, breaking meat up into small pieces with a wooden spoon. Cook until no pink remains, about 6 to 7 minutes. Use a slotted spoon to remove sausage crumbles from the pan to drain on a plate lined with paper towels.
5. Pour all but 1 Tbsp. of fat out of the pan. Return pan to medium high heat. Add onions and peppers. Cook 3 minutes to soften. Add garlic and cook 1 minute more. Add drained sausage and tomato sauce. Cook, stirring occasionally, until the sauce is heated through (about 3 minutes).
6. Spray a 9-by-13-inch baking dish with cooking spray. Spread half the sausage mixture on bottom of dish. Spread half the squash mixture over sausage mixture. Spread with remaining sausage mixture and top with remaining squash mixture. Sprinkle Parmesan cheese, if using, over the surface. (At this point, casserole can be refrigerated overnight, covered well.)
7. Bake casserole until the sauce is bubbling up around the sides and the Parmesan cheese has browned slightly, about 25 to 30 minutes, or 50 to 55 minutes if baking from the fridge. Let casserole rest for 15 minutes before serving.
Source: Hannaford fresh Magazine, January - February 2015