Place the olive oil and Italian seasoning in a small sauce pan over medium-low heat. Heat for about 1 minute, until the herbs are fragrant, then pour into the slow cooker. Add the crushed tomatoes and 1 teaspoon sea salt and stir together.
Place the squash halves into the slow cooker, cut side up, on top of the tomato mixture. Season with sea salt and drizzle with a little olive oil.
In a medium bowl, combine the turkey, egg, sea salt and black pepper. Using a spoon, scoop bite-size meatballs and place into the tomato mixture.
Place the lid on the crock pot and cook on medium heat for 4 hours. Using a fork, remove the spaghetti squash strands from the skins and serve with meatballs and marinara. I like to throw a little parmesan on top!