Bring a pot of water to boil. Add salt, pepper, and garlic powder to the water. Add the pasta and cook 1-2 minutes less than specified on the box. Once done drain the pasta, but reserve 1 cup of the pasta water.
Heat a skillet to medium high heat with 2 tablespoons of olive oil. Cut open the sausage links and remove the casings. Add to the skillet. Do not stir the meat frequently, allow it to crisp. Once lightly browned add in the sliced red onion. Meanwhile remove kale leaves from the stems. Once the meat is totally cooked through and the onions are soft add in the kale leaves. Allow the kale to wilt for about 1-2 minutes, stirring frequently. Add the reserved pasta water and begin to scrape the brown bits off the bottom of the pan.
Simmer the skillet until the liquid has reduced down by half. Turn down the heat to medium low. Add in the pasta, then sprinkle both the mozzarella and parmesan over the top. Combine all the contents of the skillet until the cheese has melted. Remove from heat and serve.