Bring a large pot of salted water to a boil. Cook pasta until al dente, about 10-12 minutes. Reserve ½ cup pasta water, then drain and set aside.
Heat 1 tbsp olive oil in a large skillet over medium heat. Add 1 lb Italian sausage, breaking it into small pieces as it cooks. Cook until browned, about 6-8 minutes. Skim off excess grease, leaving a light coating for flavor. Stir in 1 tsp oregano and a pinch of salt.
Add 1 tbsp finely diced shallots to the skillet and cook for 2-3 minutes until softened. Stir in 3 minced garlic cloves and cook for 30 seconds.
Stir in 2 tbsp tomato paste and cook for 2-3 minutes. Add one 14-oz can of diced tomatoes (with juices) and simmer for 8 minutes. Pour in 1 cup chicken broth, stirring to scrape up any browned bits from the bottom of the skillet. Simmer for 2-3 minutes.
Reduce the heat to low and stir in ¼ cup heavy cream (if using) and ¼ cup grated Parmesan cheese. Add the cooked pasta to the skillet and toss to coat. If the sauce is too thick, add reserved pasta water, 1 tbsp at a time, until it reaches your desired consistency.
Top with freshly chopped basil and more Parmesan cheese. Serve warm.