Bring a large pot of water to a boil for pasta. Salt water and cook pasta to al dente, reserve about 1/2 cup of starchy cooking water just before draining.
Meanwhile, heat a large skillet over medium-high heat with EVOO, one turn of the pan. To the hot pan add sausage, brown and crumble 5 minutes. Then add chili pepper, garlic and toss 1-2 minutes. Add cherry tomatoes and cover the pan with a tight fitting lid to burst tomatoes, 8-10 minutes. Shake the pan occasionally to move the tomatoes around a bit. When skins start to burst crack softened tomatoes open with utensil. Reserve 1/2 cup of starchy water.
Drain pasta, toss with sausage, arugula and starchy water then season with salt and pepper to taste. If you are using cream, toss the pasta an additional minute to heat the cream through. If the sauce gets too tight, loosen up with some starchy water.
If you are serving with mascarpone or ricotta, place a dollop on top of each serving for mixing in. Reminder: the pasta is fantastic as-is, as well!