Pre-heat oven to 375 degrees. Cut spaghetti squash in half length-wise and scoop out seeds. Rub cut sides of spaghetti squash with half of the olive oil and season with 1/2 tsp Italian seasoning.
Place spaghetti squash on a lined baking sheet with cut side up. Bake for 35-40 minutes or until the flesh of the squash flakes easily with a fork. Set aside to cool.
Heat large skillet over medium-high heat. Add olive oil. Once hot, add onions and garlic and sauté until fragrant. Add turkey and sausage.
Break apart turkey and sausage with a wooden spoon continuously. Once cooked most of the way through, add crushed tomatoes, tomato sauce, and remaining Italian seasoning.
Lower heat to a simmer and continue cooking bolognese sauce for about 20 minutes.
Serve bolognese sauce over spaghetti squash.