Bring a large pot of water to a boil over high heat. Add 16 ounces rigatoni and cook to desired doneness 10-12 minutes. Drain and set aside.
In large heavy bottom skillet over medium high heat, cook 1 pound ground pork, 1 tablespoon smoked paprika, ½ teaspoon fennel seed, ½ teaspoon kosher salt, and ⅛ teaspoon red pepper flakes until sausage is browned and crumbly. This should take about 5-8 minutes. Remove from pan and set on paper towel lined plate.
In same pan, melt 1 tablespoon unsalted butter. Add 16 ounces sliced mushrooms and 1 diced shallot. Continue cooking over high heat, stirring only occasionally, so that you get a nice brown sear. When mushrooms and shallot are just about done, add 2 cloves minced garlic, stir, and cook for another minute.
Add 2 cups heavy whipping cream to mushroom mixture, stir well, and allow to come to a boil. Reduce heat until mixture is at a gentle simmer and allow to cook uncovered until slightly thickened, about 10 minutes. Add cooked sausage back into the cream sauce and stir to combine. Add salt and pepper to taste .
To serve, ladel mushroom sausage cream sauce over cooked rigatoni and top with grated parmesan for garnish and sliced fresh basil for garnish.