Cut spaghetti squash in half, crosswise. Place in the bottom of a 6 quart slow cooker, cut-side down.
In a processor or blender, combine tomatoes, salt, garlic powder, pepper and oregano. Puree until smooth. Pour into bottom of slow cooker.
Place meatballs over tomatoes, around spaghetti squash. Cook on low for 6 to 7 hours or on high for 3 to 4 hours.
Using tongs and kitchen gloves, remove spaghetti squash from slow cooker. Scoop out seeds and discard.
Scoop out flesh into a sieve or colander and let drain a few minutes to reduce moisture. Transfer to a bowl and toss with butter or olive oil.
Divide between 4 plates and top with sauce and meatballs.
Serving Size 4 Servings.
Servings 1
* Percent Daily Values are based on a 2,000 calorie diet. Your daily value may be higher or lower depending on your calorie needs.