This recipe was originally published in A Girl and Her Pig before being fine-tuned by J. Kenji López-Alt of Serious Eats.
You'll wonder how the texture—nearly melting ricotta cheese—is even possible on this planet. The magic spell (hate to ruin it for you) is actually a three-day, entirely hands-off preparation process: Stir together the cheeses, season with salt, form the mixture into balls, roll each one in semolina flour, then bury those in a pile of that flour and refrigerate for three days before boiling, briefly, in salted water.
If you're going to make the butter sauces, be sure to read the complete instructions before you begin cooking the gnudi. These final steps are the fussiest and the most hands-on: You melt butter in a nearby frying pan as the gnudi boil; then you transfer the cooked gnudi and splashes of their pasta water to the butter pan, turn the heat to high, and stir and shake the dumplings until they're covered with an emulsified butter sauce. This movement threatens the integrity of the fragile gnudi—and it's also difficult to make sure the butter sauce comes together with those baby gnudi in the way.
To avoid this precarious set-up, you can cut back the multitasking (I know, I know). Instead of simultaneously emulsifying butter sauce and tossing it with the gnudi, you can make beurre monté (emulsified butter sauce) as the gnudi cook, using a splash of their cooking liquid, and then spoon it over the cooked dumplings, flipping them very gently.
Or, skip the butter sauces entirely: The gnudi can hold the plate on their own. —Sarah Jampel