In a small bowl stir together the ricotta and lemon zest. Season with salt and set aside.
Bring a large pot of water to a boil. Add 2 tablespoons of the salt and bring back to a rolling boil. Add the pasta and cook until al dente according to package directions.
While the pasta cooks, prepare the sauce: Heat the oil in a 12-inch skillet over medium heat. Add the sausage and cook until it begins to brown, about 7 minutes.
About 1 minute before the pasta is finished cooking add the snap peas to the pasta pot. Reserving 1 cup of the pasta water, drain the pasta and snap peas and add them directly to the skillet with the sausage. Toss the pasta and the snap peas to coat until they become glossy, adding 1/4 cup of pasta water (up to 1 cup) as needed to loosen the sauce.
Plate in bowls and top each with a spoonful of the ricotta mixture and sprinkle of the mint. Season with flaky salt, if desired.