Heat oil in a large wide heavy pot over medium-high. Add pork to pot, breaking apart into large chunks with a wooden spoon. Cook, undisturbed, until well browned underneath, about 5-7 minutes. Stir and continue to cook until pork is well browned, about 5 minutes longer.
Add ginger, garlic, and sugar. Cook about 5 minutes longer.
Add tomato paste and basil, stirring occasionally, until paste darkens, about 2 minutes.
Add sriracha, chili crunch, soy sauce, vinegar, and 2 cups stock. Bring to a simmer, reduce heat to low, and cook, uncovered and stirring occasionally, until sauce is slightly thickened and flavors have melded, 30–45 minutes.
Cook noodles in a large pot of boiling salted water, stirring occasionally, until 1 minute short of al dente.
Add to pot with sauce along with butter and a splash of pasta cooking liquid. Simmer, tossing occasionally, until sauce begins to cling to noodles, about 1 minute.
Plate, topped with cilantro, peanuts and scallions.