Pinch of red-pepper flakes, plus more for serving (optional)
1 (28-ounce) can whole peeled tomatoes with their juices
1 (14-ounce) can crushed or strained tomatoes
2 bay leaves
12 ounces dried pasta, such as small shells, farfalle or other shaped pasta
8 ounces fresh mozzarella, torn into bite-size pieces
6 ounces whole-milk ricotta (about ¾ cup)
⅓ cup grated Parmesan
¼ cup basil leaves
Black pepper, for serving
Preheat oven to 425 degrees.
Heat oil in a 12-inch ovenproof skillet over medium-high. Crumble sausage into skillet. Cook until starting to brown, stirring occasionally, 5 to 7 minutes.
Stir in garlic, oregano, fennel seeds and red-pepper flakes (if using), and cook another 1 to 2 minutes.
Stir in whole tomatoes and their juice, using a spoon to break them up.
Add crushed tomatoes, bay leaves and 2 teaspoons salt, and bring to a simmer. Simmer for 10 minutes to thicken slightly.
Stir in pasta and 1 cup water and return to a simmer. Continue to simmer for 2 minutes, stirring frequently to make sure pasta doesn’t stick to the bottom of the pan.
Remove from heat, pluck out the bay leaves, and fold in about a third of the mozzarella.
Top pasta with remaining mozzarella and dollops of ricotta. Sprinkle with Parmesan, then transfer to oven.
Bake until pasta is tender when poked with a fork, and cheese is bubbly and lightly golden, 18 to 22 minutes. (If you’d like a more deeply browned topping, run the pan under the broiler for 1 or 2 minutes.)
Remove from oven and let cool slightly before serving.
You can top with basil, plenty of black pepper, and more red-pepper flakes, to taste, or enjoy as is.