Preheat the oven to 425℉ / 218℃.In a medium dutch oven or a large skillet, add 2 tablespoons extra-virgin olive oil and melt 2 tablespoons unsalted butter over medium-low heat. Add 2 cloves garlic, thinly sliced, 1 filet anchovy, and ¼ teaspoon red chili flakes, and saute until aromatic, about 1 - 2 minutes.
Stir in 8 ounces fresh cherry tomatoes, and saute until they just begin to wrinkle, about 3 - 5 minutes.
Add 14 ounces canned whole peeled tomatoes and season with salt. Simmer for 10 - 12 minutes until the cherry tomatoes burst and the sauce has thickened slightly. Crush any remaining whole tomatoes with the back of a spoon.
For homemade gnocchi: Meanwhile, bring a large pot of salted water to boil. Add 12 ounces potato gnocchi and cook until they float to the top. Using a slotted spoon, transfer the dumplings to the dutch oven and toss to combine with the sauce. For store-bought gnocchi: I find store-bought gnocchi are at their best when they're crisped up slightly in a pan. Instead of boiling them, I recommend sauteing them with a tablespoon or two of oil over medium heat. Allow them to crisp up in the pan until lightly golden-brown. Then, toss to combine with the sauce.Note: The sauce-to-gnocchi ratio can vary depending on the exact ingredients you use. The gnocchi shouldn't be *drowning* in sauce, but they should look a little more saucy than you'd like (since the sauce will thicken in the oven). If it appears to dry, feel free to add a bit more canned tomato juice or water.
Season with salt to taste. Transfer half of the saucy gnocchi mixture to an oven-safe casserole dish. Top with half of the 4 ounces fresh whole-milk mozzarella, then top with the remaining gnocchi mixture, followed by the remaining mozzarella. Finally, sprinkle on the parmigiano-reggiano cheese.
Bake in the oven for 10 - 15 minutes, or until the sauce has thickened slightly, and the cheese is bubbly, fully melted, and slightly golden-brown. Remove from the baking dish from the oven and cool for a few minutes to allow the sauce to set. Garnish with basil, and serve.
This dish has a relatively small amount of ingredients, so every ingredient counts! Try to use the best gnocchi, mozzarella, and tomatoes you can find. * Gnocchi: Store-bought gnocchi taste a bit gummier than homemade, but they're still delicious in this recipe. I recommend Mamma Emma (can be found at Eataly) or DeCecco (can be found in most grocery stores) brands.Mozzarella: I prefer a fresh mozzarella here, like fior di latte (cow's milk) or mozzarella di bufala (buffalo milk), so look for a nice ball of cheese in liquid when grocery shopping.For best results, remove the baking dish from the oven while the sauce is still a bit liquidy and the gnocchi are still soft and tender, as everything will continue to firm up once cooled down.Storage: Leftover gnocchi sorrentina can be stored in an airtight container in the fridge for 2-3 days. You can quickly reheat individual portions in the microwave, or reheat larger portions in an oven safe dish in the oven. Bake, covered with foil, at 350°F/177°C for 5-10 minutes until warmed through.