Baked Pasta With Merguez and Harissa-Spiked Sauce

Preheat oven to 400 °F. Grind caraway and cumin in a spice mill or a mortar and pestle; set aside. Heat oil in a large skillet over medium. Cook sausage until browned all over but still pink in the center, about 3 minutes per side. Transfer to a cutting board and let cool slightly. Slice into 1" pieces. Add onion to same skillet and cook, stirring often, until soft, 6 –8 minutes. Add garlic and reserved spices. Cook, stirring, until fragrant, about 2 minutes. Add tomatoes, crushing, and juices, then harissa. Cook until sauce thickens slightly, 6 –8 minutes. Season with salt and pepper. Meanwhile, cook pasta in a large pot of boiling salted water until very al dente (about 3 minutes less than package directions; it will be firm in the center). Drain, reserving 1/4 cup cooking liquid. Add sausage, pasta, and cooking liquid to skillet; toss to coat. Transfer to a 3-quart baking dish, top with feta, and bake until top is browned and juices are bubbling, 18 –22 minutes.