Cut the squash in half lengthwise using a serrated knife. Scoop out and discard the seeds with a spoon. Put the squash onto a microwave safe plate, cover tightly with plastic wrap and microwave on high for 13-14 minutes, until tender and the flesh can easily be detached with a fork.(See below for alternative spaghetti squash cooking methods using the oven or instant pot.) Use a fork to scrape the inside of the squash into spaghetti-like strands and place into a bowl.
In a separate bowl, mix together the parmesan cheese, egg yolks, salt and pepper and set aside.
Cook the pancetta in a large skillet over medium-high heat, stirring occasionally, for about 7-8 minutes, until crisp. Add the garlic and red pepper flakes to the skillet and cook, stirring for about 1 minute, until the garlic is fragrant. Stir in the heavy cream, scraping up any brown bits in the pan, and bring to a simmer. Reduce the heat to medium-low and add the squash strands. Toss together until squash is coated.
Add the parmesan and egg mixture slowly and toss to gently cook the eggs and make a creamy sauce. Turn off the heat and stir in the parsley. Divide among 4 plates and serve with more Parmesan and parsley for garnish if desired.
This recipe makes 4 servings. Serving size will vary depending on the exact size of the spaghetti squash you use, etc. One serving is roughly 1 cup-1.5 cups of the prepared carbonara.Oven and Instant Pot Spaghetti Squash Cooking Options:Oven Method: 400 degrees for 30-40 minsSlice the spaghetti squash in half lengthwise and scoop out the seeds. Drizzle the inside of the squash with olive oil and sprinkle with salt. Place the spaghetti squash cut side down on the baking sheet and use a fork to poke holes. Roast for 30 to 40 minutes or until lightly browned on the outside, and slightly tender on the inside.Instant Pot Method: 7 Minutes on highPlace a trivet or steamer basket in the Instant Pot and add a cup of water, cut the squash in half, scoop out the seeds, then place the cut squash halves on top of the trivet/steamer basket and secure the lid and set to seal. Use the pressure cook or manual button to set the pressure cooker to cook at high pressure for 7 minutes.