Bring large pot of heavily salted water to a boil over high heat. Add rigatoni and cook to desired doneness (I prefer slightly al dente). Drain and set aside.

Meanwhile, in large heavy bottom skillet or dutch oven over medium high heat, cook ground pork, paprika, fennel, kosher salt, and 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 butter. Add mushrooms and 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 garlic, stir, and cook for another minute.

Add 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 garnish with grated parmesan and fresh basil ribbons.