Spaghetti Squash Puttanesca

Name: Spaghetti Squash Puttanesca
Ingredients: 1 large spaghetti squash (about 4 lbs / 1.8 kg); 2 tablespoons olive oil, plus additional for drizzling; 1 small onion, finely chopped; 4 cloves garlic, minced; Three 15 oz (425 g) cans plum tomatoes, (an imported italian brand like San Marzano is best); One 7 oz (200 g) can tomato paste; ¾ cup (180 g) olives, pitted and sliced in half; 2 tablespoons capers, drained; One 2 oz (115g) tin anchovy fillets, minced; 1 teaspoon dried basil; 1 teaspoon dried oregano; ½ teaspoon dried red pepper flakes; 1 teaspoon sea salt; ¾ teaspoon freshly ground black pepper