Preheat oven to 400° F. Bake potatoes on a sheet pan until fork tender, about 1 hour.
When cool peel potatoes and grate them on the small grates of a cheese grater.
Line a baking sheet with paper towels.
Place potatoes on the counter and sprinkle with the flour and salt and gently mix together.
Separate dough into quarters and working with one piece at a time roll the dough into a 1 inch thick rope.
Cut each rope into 1 inch pieces, you should have around 65 pieces.
Turn a fork upside down and roll each piece of dough over the fork prongs making lines all the way across each piece of dough. Place the pieces on the paper towel lined sheet and let sit for 1 hour.
In a large pot bring 2 quarts salted water to a boil. Gently place the gnocchi pieces in the water but do no allow the water to reboil. Allow the gnocchi to float to the top and bob there for about 3 minutes and remove with a slotted spoon.
Heat a large saute pan over medium heat and add the butter, shallots and sage.
Tilt the pan back and forth, butter will get foamy. When foaming subsides and starts to brown and sage begins to crisp take off the heat and add the gnocchi and toss to coat.
Season with the salt and pepper to taste and top with the freshly grated Parmesan cheese.