1. Before you start preparing anything, preheat the oven to 375°F (190°C).
2. Cut the spaghetti squash in half lengthwise and scoop out the seeds from inside of the squash either now or later once it’s baked – then drizzle olive oil over the cut halves of the squash and season with salt and pepper to taste before you place cut side down on a baking sheet.
3. Roast in the preheated oven for about 35-45 or until it’s tender and the flesh can be easily scraped with a fork – make sure not to overcook it or it can turn out watery, it should be fork tender.
4. Meanwhile, prepare the carbonara sauce in a large skillet or pan by adding the diced bacon or pancetta pieces to it and cooking them over medium-high heat until they become crispy.
5. Take off the bacon or pancetta and set aside, reserving the bacon grease in the pan, then add the minced garlic and cook for 1 minute until it’s fragrant. 
6. Take a large bowl and whisk together the raw eggs, heavy cream, Pecorino Romano cheese, Parmesan cheese, and a pinch of black pepper – mix it until it’s all well combined.
7. Check on your squash and remove it from the oven when it’s cooled, then let it cool slightly before you use a fork to scrape the flesh into spaghetti-like strands.
8. Back to the skillet, reduce it to low heat and add the roasted spaghetti squash strands to the skillet – combining everything as you’re tossing it gently to combine.
9. Use the egg mixture from step 6 and add it to the skillet with the squash, stirring quickly to coat the squash evenly around – just make sure not to overcook the eggs or they will scramble.
10. Lastly, add the cooked crispy or pancetta to the skillet, mixing everything together – finally, seasoning with salt and black pepper to taste.

Serve it hot with chopped fresh parsley either inside the squash or in a separate bowl.