Creamy Farfalle Pasta: Sausage & Spinach Delight!

Ingredients

• 1 pound (454g) farfalle pasta
• Salt, for pasta water (to taste - about 1 tablespoon)
• 1 tablespoon (15ml) olive oil
• 1 pound (454g) Italian sausage, casings removed
• 1 medium yellow onion, finely chopped (approx. 1 cup)
• 2 cloves garlic, minced (approx. 2 teaspoons)
• 1/2 teaspoon red pepper flakes (or more, to taste)
• 1 (28 ounce/794g) can crushed tomatoes
• 1/2 cup (120ml) heavy cream
• 5 ounces (142g) fresh spinach, roughly chopped
• 1/4 cup (60ml) grated Parmesan cheese, plus more for serving
• Salt and black pepper, to taste