Preheat oven to 350⁰ F. Grease sheet pan with a 1/2 teaspoon olive oil or cooking spray.
Using a sharp knife, cut the acorn squash in half to create 2 squash bowls. To allow each squash bowl to stand up straight, carefully slice 1/4 inch off the rounded end of the squash. Scoop out the seeds and fiber from the squash and discard. Rub the outside of each hollowed squash half with 1/2 teaspoon olive oil and place on prepared sheet pan with open end up, set aside.
Heat a large sauté pan over medium heat. Add 2 tablespoons of olive oil and onion to pan, sauté for 2-3 minutes. Add garlic to pan, saute for 30 seconds. Add carrots, parsnips, and cooked sorghum to pan, sauté for 10 minutes. Add apple cider, balsamic vinegar, sorghum syrup, water, dried prunes, dried cranberries, and walnuts to pan – mix together, cover, and simmer for another 10 minutes.
Ladle 1 1/2 cups of mixture into each hollowed squash. Sprinkle evenly, each stuffed acorn squash, with chopped walnuts. Bake for 60 minutes, check for doneness by inserting a fork in the side of squash. Once fork can easily pierce through the squash, remove from oven. If squash is still hard, cook an additional 30 minutes until soft, checking periodically. Serve warm.