1. Preheat the oven to 375 degrees F (190 degrees C). Line a baking sheet with parchment paper or foil.
2. Using a sharp knife, cut off the root end of the squash, cut in half lengthwise, and scrape out the seeds and connecting strands with a spoon. Brush the cut sides with olive oil and place squash on the baking sheet with cut sides down.
3. Bake until the skin can be easily pierced with a fork, and the flesh is tender, about 45 minutes.
4. While squash is baking, cook bacon over medium heat until crispy and browned, 3 to 4 minutes. Remove to a paper towel to drain.
5. Remove squash from the oven and let rest until cool enough to handle. Scrape out the flesh with a fork creating long strands, loosening and removing the strands from the shells.
6. Heat a large pan on medium heat, and melt butter. Add garlic and cook until fragrant, about 30 seconds. Add squash strands, toss with garlic butter, and cook until heated through, stirring often, about 2 minutes.
7. Remove pan from the heat, stir in Parmesan cheese, and season with salt and pepper. Gently stir to coat the strands and let the cheese melt. Garnish with bacon, oregano, and red pepper flakes.

Cook’s Note:
As an option, you also may serve the finished spaghetti squash in the squash shells.