Pillowy Gnocchi alla Sorrentina with Bubbling Mozzarella

Place the whole, unpeeled potatoes in a large pot of cold salted water. Bring to a boil and cook until a knife slides through easily, about 35-40 minutes. Drain and let cool just enough to handle.

While potatoes cook, make the sauce. Heat olive oil in a saucepan over medium heat. Add the smashed garlic and red pepper flakes, cooking until the garlic is golden and fragrant, about 2 minutes. Crush the tomatoes by hand and add them to the pan with a pinch of sugar, salt, and half the basil leaves. Simmer gently for 20 minutes, stirring occasionally. Remove garlic cloves and adjust seasoning.

Peel the warm potatoes and pass them through a potato ricer or food mill onto a clean, lightly floured surface. Let the riced potatoes cool for a few minutes so they stop steaming.

Sprinkle 1 cup of flour over the potatoes, add the egg yolk and a pinch of salt. Gently bring everything together with your hands, folding rather than kneading. Add more flour only as needed -- the dough should be soft, slightly tacky, and tender. Overworking creates dense gnocchi.

Divide the dough into 6 portions. Roll each into a long rope about 3/4 inch thick, then cut into 1-inch pieces. Optionally roll each piece over the tines of a fork to create ridges.

Preheat the oven to 425 degrees F. Bring a large pot of generously salted water to a rolling boil.

Drop the gnocchi into the boiling water in batches. They are done when they float to the surface, about 2-3 minutes. Remove with a slotted spoon and place directly into a large baking dish.

Pour the tomato sauce over the gnocchi and gently toss to coat. Scatter the torn mozzarella and half the Parmigiano-Reggiano over the top.

Bake for 15-18 minutes until the mozzarella is melted, stretchy, and spotted with golden brown patches.

Remove from the oven, scatter with fresh basil leaves and the remaining Parmigiano. Let rest for 5 minutes before serving.