Boil a large pot of salted water and cook spaghetti according to package instructions until al dente, about 8-10 minutes. Reserve ½ cup of pasta water, then drain and set aside.

In a large skillet over medium heat, cook thick-cut bacon for 5-7 minutes until crispy. Remove and drain on paper towels, then chop into bits.

Sauté sliced mushrooms in the remaining bacon grease for 5-7 minutes until browned and tender. Optionally add olive oil if needed.

Add minced garlic to the mushrooms and cook for an additional minute until fragrant. Stir in dried thyme, smoked paprika, salt, and pepper.

Return the pan to low heat and stir in pumpkin puree, mixing well and cooking for 2-3 minutes.

Pour in heavy cream and grated Parmesan cheese; increase heat slightly and simmer for 2-3 minutes until the sauce thickens.

Lower heat and toss the drained spaghetti into the sauce, adding reserved pasta water if the sauce is too thick.

Serve warm, topping with crispy bacon bits and fresh parsley.