Place a large pot of salted water on cooktop to boil.

While waiting for water to boil, chop sage leaves, toast pine nuts and brown butter:

Chop sage leaves. Place a small sauce pan on medium heat, add pine nuts. Allow them to toast until lightly golden tossing a few times to prevent burning. Do not walk away! (I can not tell you how many times I have burned pine nuts) When nuts are slightly golden place in a bowl and set aside.

Allow pan to cool for a minute, then add 1/2 cup butter (one stick) to same small sauce pan. Allow butter to melt slowly. After a few minutes the butter will begin to bubble up. Stir occasionally and keep an eye on the butter, this will take a few minutes, do not rush the process by turning up heat. After 4-5 minutes the center will erupt in a caramel color. The butter is now browned. Immediately turn off heat and add chopped sage leaves. They will 'fry' in the butter and become crispy.

Cook pasta to package directions. While it cooks, grate parmesan.

Strain pasta, pour onto a platter, drizzle with brown butter, sprinkle with cheese, sea salt, pepper and red pepper flakes (if using). Garnish with pine nuts and extra sage leaves if desired. Serve!