Bring a large pot of salted water to boil. Cook pasta until al dente, reserving 1 cup pasta water before draining.
While pasta cooks, gently warm olive oil in a skillet over medium-low heat.
Add thinly sliced garlic and a generous pinch of cayenne or red pepper flakes. Cook slowly 3–4 minutes until garlic is pale gold. Low and slow prevents burning, which makes it bitter.
Add canned tomatoes and break them up with a spoon. Season with salt.
Simmer 12–15 minutes until sauce thickens and turns a deep red.
Taste — it should be spicy, sweet, and rich. Adjust cayenne to your heat tolerance.
Add drained pasta directly to sauce with a splash of pasta water. Toss vigorously over medium heat for 1–2 minutes. The starchy water helps emulsify the sauce.