Preheat oven to 400°F and line a baking sheet with parchment paper.
Toss butternut squash cubes with 1 tablespoon olive oil, salt, and pepper, then spread on baking sheet and roast for 20-25 minutes until tender and lightly caramelized.
While squash roasts, heat remaining olive oil in a large cast iron skillet over medium-high heat and cook sausage, breaking it up with a spoon, until browned and cooked through, about 6-8 minutes.
Add diced onion and bell pepper to the skillet and cook until softened, about 5 minutes.
Stir in minced garlic, smoked paprika, and thyme, cooking for another minute until fragrant.
Add roasted butternut squash to the skillet and toss everything together, cooking for 2-3 minutes to combine flavors.
Taste and adjust seasoning as needed, then garnish with fresh parsley before serving.