Preheat and prep: Heat your oven to 400°F (200°C). Line a baking sheet with parchment for easy cleanup.

Cut the squash: Carefully slice the spaghetti squash in half lengthwise. Scoop out the seeds with a spoon. Drizzle the cut sides with 1 tablespoon olive oil and season with salt and pepper.

Roast: Place squash halves cut-side down on the baking sheet. Roast for 35–45 minutes, depending on size, until the flesh is tender and shreds easily with a fork.

Cool and shred: Let the halves cool for 5–10 minutes so they’re easier to handle. Use a fork to pull the strands into “spaghetti.” Transfer to a bowl and set aside.

Build the sauce: In a large skillet over medium heat, warm 2 tablespoons olive oil and the butter. When the butter melts and foams slightly, add the minced garlic. Cook 30–60 seconds, stirring, until fragrant. Don’t let it brown.

Add lemon and heat: Stir in lemon zest, lemon juice, and crushed red pepper flakes if using. Let the sauce bubble for 30 seconds to meld.

Toss it all together: Add the shredded spaghetti squash to the skillet. Toss to coat evenly. Cook 2–3 minutes to warm through and let the squash absorb the flavors.

Cheese and herbs: Turn off the heat. Sprinkle in Parmesan and parsley. Toss again until the cheese melts slightly and everything looks glossy.

Taste and season: Add more salt, pepper, or lemon juice to taste. For extra richness, swirl in another small knob of butter.

Serve: Plate with extra Parmesan on top. Add your favorite protein or toppings if you like.