Halve squash lengthwise; scoop out seeds. Place squash, cut-side down, in a baking dish. With a fork, prick the skin all over. Bake in a preheated 350 degrees F oven for 30-40 minutes, or till tender.

Meanwhile, for sauce, fill a large saucepan with water; bring to boiling. Core tomatoes; plunge into boiling water for 30 seconds to loosen skins. Transfer tomatoes to a colander; rinse with cool water. When tomatoes are cool enough to handle, remove skin. Halve peeled tomatoes crosswise. Squeeze out seeds; discard. Chop tomatoes; set aside.

In a large skillet heat oil; cook and stir green onions and garlic for 2 minutes. Add tomatoes, basil, salt, sugar, and pepper. Bring to boiling; reduce heat. Simmer, uncovered, for about 5 minutes, or till mixture is of desired consistency. Using a fork, separate the squash pulp into strands; mound on a serving platter. Spoon tomato sauce over squash.