Roasting the Squash

1. Preheat your oven to 400°F (200°C).
2. Place the squash halves on a baking sheet, cut side up. Drizzle with olive oil and sprinkle with salt and pepper.
3. Roast for about 40 to 50 minutes until fork tender.
4. If the squash is browning too fast, loosely cover with foil for the last 10 minutes.

Preparing the Filling

1. While the squash roasts, cook chopped bacon in a skillet over medium heat until crisp. Remove and place on paper towels.
2. In the retained bacon fat, sauté garlic for about 30 seconds until fragrant.
3. Add spinach to the skillet and stir until wilted. Remove from heat and mix in cream cheese until melted.
4. Stir in the shredded cheese, bacon, and optional sour cream or yogurt.
5. Season with salt and pepper to taste.

Stuffing and Final Baking

1. Once the squash is tender, scoop out some of the flesh to create a cavity.
2. Mix the scooped squash into the filling, then spoon the mixture back into the squash halves.
3. Top with additional shredded cheese if desired.
4. Return to the oven for 10 to 15 minutes until heated through and melty.
5. Broil for 1 to 2 minutes if you want a browned cheesy top.
6. Let it rest for 5 minutes before serving.