With a vegetable peeler, shave the asparagus lengthwise into long ribbons.
Cook the spaghetti according to the package directions, adding the asparagus during the last 2 minutes of cooking.
Drain the spaghetti and asparagus and return them to the pot.
Add the oil and hazelnuts; toss. Add the salt and pepper; toss again.
Divide the spaghetti among individual plates. With the peeler, shave the Parmesan over the top.