Boil water and salt in a pan (large enough to hold to ears of corn). Add the ears and cook for about 10 minutes.
Take the ears out of the water and allow to cool
Add the pasta to the hot 'corn water' and cook the pasta according to the directions on the packaging.
Remove the kernels from the corn.
Melt the butter in a skillet and add the scallions and the corn. Cook for a few minutes to soften the scallions.
Transfer most of the scallion/corn mixture into a blender and pulse until you have a sausy substance. Add pasta water if needed to thin out the puree/sauce.
Drain the pasta and transfer back in to the pan, add the corn puree as well as the reserved kernels.
Mix with grated Parmesan cheese and finely chopped parsley.