Bring a large pot of water to a boil and salt generously.
Heat a large frying pan over medium heat; swirl in 2 tbsp. oil. Add onion and a pinch of salt. Cook until tender, stirring occasionally, about 20 minutes. It's okay if onion picks up color, but don't let it burn; add a splash of water if you need to. Stir in chile and garlic; cook 1 minute.
Add half of tomatoes and cook until jammy, stirring often, about 10 minutes. "Let them cook until they collapse and start making syrupy bubbles," says Nosrat.
Boil orecchiette until tender to the bite, 7 to 10 minutes if fresh, 15 to 20 if dried.
Scoop out pasta and add to pan, along with remaining tomatoes and half of marjoram. If pasta looks dry, add a little oil and pasta water. If you like, stir in some ricotta salata. Spoon into bowls and top with ricotta and remaining marjoram.
*Because store-bought pasta is thinner than homemade, you get more pieces per pound.
Serves 6 to 8