I wish I had learned this a long time ago when I attempted to make my Grammy Filomena’s gnocchi and it was a disaster. Bake the potatoes, don’t boil them. Water is the enemy of good gnocchi, and you can spend HOURS ( which I did) trying to get the moisture out of the dough. That in turn, creating gnocchi that were equivalent to little bricks rather than pillows.
Bake the potatoes, don't boil them in water. Cook the potatoes by piercing each of them several times with a fork.
Rice the potatoes with a fine potato ricer. Avoid mashers and food mills, which compress the potatoes. You want to produce tiny crumbles that will release yet more moisture, producing extra-light gnocchi.
If you want to be true to Italian gnocchi, look for imported Italian flour marked "00 tenero," which is milled from soft wheat with a low protein content. High protein wheat flour makes chewy hard gnocchi. You can find Anna 00 flour in most grocery stores. Also you can order 00 flour on Amazon.
You'll need about one cup of flour for every pound of riced potato — more if the potatoes are very young, or if it's quite humid out.
You will need:
2 pounds (about 4) baking potatoes, like russets
1 teaspoon salt
1/2 teaspoon baking powder
1 1/2 cups 00 flour ( you may need more but start with this)
Pierce the potatoes several times so that moisture can escape during baking. Bake the potatoes in a preheated 400 degrees F oven for 1 hour until fork tender. Peel the potatoes while they are still hot and press them through a potato ricer. Put the potatoes in a large bowl with salt, baking powder, and egg. Add the flour a little at a time and mix with your hands until the mixture forms a rough dough. Do not over-work the dough. Transfer the dough to a lightly floured surface. Gently knead the dough for 1 or 2 minutes until smooth, adding a little bit more flour, if necessary, to keep it from sticking.
Break off a piece of the dough and roll it back and forth into a rope, about the thickness of your index finger. Cut the rope into 1-inch pieces. Gently roll each piece down a wooden gnocchi board while pressing a small dimple with your finger. Or just use your middle finger and ring finger, press into dough and pull toward you forming a C shape. This will allow the pillows to hold sauce when served.
Boil the gnocchi in batches in plenty of salted water. The gnocchi are done about 2 minutes after they float to the surface, remove with a slotted spoon, and serve. If not cooking immediately, place the gnocchi in a single layer on a baking pan dusted with flour. Cover with plastic wrap and refrigerate for up to 12 hours.
Note: If the gnocchi start to feather and fall apart in boiling water, you need more flour. If the gnocchi don't float after 2 minutes and are hard, you used too much flour.