Set the scallops on a plate and allow them to come to room temperatures. Make sure to retain any of the liquid from the scallops that settles on the plate. You'll want to start making the asparagus ribbons at and start the pasta water at this point.
Bring a large pot of lightly salted water to a boil. Add the spaghettini and cook until al dente. Drain and set aside, but do not rinse or cool.
Whisk the lemon juice and olive oil together in a bowl. Add the spaghettini back to a large pot, then add the lemon juice, olive oil, grated parmigiano-reggiano, and the smaller portion (1 tbsp) of butter. Stir to combine, making sure that the cheese melts from the heat of the pasta. Cover and set aside.
Heat a frying pan over medium-high heat for about 1 minute. The pan should be large enough to hold all of the scallops without crowding. Add the larger portion (2 tbsp) of butter to the pan and swirl around to let it melt and begin browning. Add the scallops to the pan carefully, making sure to give each one some space. Reduce the heat a little bit and sear until well- browned, then turn carefully and sear the other side. Cook the scallops until the center is still somewhat translucent (the actual time necessary will vary depending on the size of the scallops), then remove from the pan and set aside.
Add the asparagus ribbons, white wine, and any leftover liquid from the scallops to the pan. Saute until the asparagus is soft but still vibrant green; about 1 minute.
Add the contents of the pan to the spaghettini and carefully combine. Serve each portion of spaghettini garnished with chopped parsley, black pepper, lemon zest, and extra parmigiano-reggiano. Top each dish off with an individual portion of scallops and serve immediately.