Cut the cauliflower into medium florets. Add to a pot of salted, boiling water and let simmer for 10 minutes until very soft. Drain and tip into the jug of a blender.
Meanwhile heat the olive oil in a medium skillet over a medium-low heat. Add the onion and cook until softened and slightly golden – about 15 minutes. Add the garlic and stir for 1 minute then from from the heat. Tip into the jug of the blender along with the vegan cream cheese, vegetable broth, salt, soy sauce, apple cider vinegar, nutritional yeast and a generous pinch of black pepper. Blitz until silky smooth.
Cook the pasta in a large pot of boiling water according to the directions on the packet. Drain and return to the pot. Pour in the cauliflower sauce and stir together. Taste and add more salt and pepper if needed. Divide between bowls and serve with a drizzle of olive oil on top.