Preheat oven to 400°. Poke potatoes all over with a fork. Place directly on oven racks and roast potatoes until easily pierced with a knife, about 1 hour. Let cool slightly.
When potatoes are cool enough to handle, cut in half and scoop out insides. Discard skins. Run potatoes through a ricer or mash well with a fork. Transfer to a large bowl. Add eggs, all-purpose flour, and salt and mix with a wooden spoon until a dough forms.
Turn out dough onto a lightly floured surface and knead until smooth, about 3 minutes.
Sprinkle a layer of semolina flour on a baking sheet. Divide dough into 4 pieces. Using your hands, roll each piece to a long rope about ½" in diameter. Cut ropes into 1" pieces. Arrange pieces on baking sheet. Gently toss in semolina to coat. If dough is too soft to work with at this point, freeze 10 minutes. Using the back of a fork, roll each piece of dough along the tines to create ridges and return to baking sheet.
In a large pot of boiling salted water, cook gnocchi until it floats to the top, about 2 minutes. Using a slotted spoon, transfer gnocchi to preferred sauce and toss to coat.
