Make the pasta: In a medium mixing bowl, combine the flour and the water and mix with a wooden spoon until a crumbly dough is formed. Use your hands to press the dough into a rough ball. It may feel very dry at first, but the flour will continue to hydrate as you work the dough. Transfer the dough to a clean work surface and begin to knead it. The dough should be fairly stiff and won’t require much, if any, added flour during the kneading process, but add a small dusting if the work surface becomes sticky. Continue to knead the dough until smooth and supple, 8 to 10 minutes. Cover tightly with plastic wrap and let rest in the refrigerator for at least 30 minutes and up to a couple hours. Cut the dough into 4 equal pieces. Work with one piece at a time and keep the remaining dough lightly covered in plastic while you work to keep it from drying out. Roll each piece of dough into a ½-inch-thick rope, then cut the rope into ½-inch pieces. Take each piece of dough and roll it firmly down a gnocchi board or the back of the tines of a fork. Press firmly so that the dough curls over itself, creating a hollow in the center of each piece. Transfer the gnocchetti sardi to a sheet pan and toss them in a generous amount of semolina flour to keep them from sticking to each other. Use immediately or freeze for up to 3 months. (Freeze pasta in a single layer on a sheet pan and, once fully frozen, transfer to an airtight container.) Make the sauce. Heat oil in a large saucepan over medium heat. Add the garlic and cook, stirring constantly for 10 to 20 seconds or until fragrant but not browned. Add the tomatoes and a large pinch of salt. Cover and cook for about 3 minutes, or until the tomatoes start to break down. Uncover the pan and use the back of a wooden spoon to mash and further break down the tomatoes. Continue to cook the sauce, stirring occasionally, until it reduces and thickens slightly, another 5 to 8 minutes. Adjust seasoning to taste. Cook the pasta. Bring a large pot of salted water to a boil over high heat. Once boiling, add the pasta and cook for 2 to 3 minutes or until al dente. Reserve ½ cup of pasta water before draining. Add the drained pasta to the sauce along with a splash of the reserved pasta water. Toss vigorously to coat. Serve topped with a dollop of ricotta, a drizzle of olive oil, a handful of fresh torn basil, and gratings of Parmesan cheese.