Cook your rigatoni according to the packet instructions. Reserve 1 cup of pasta water before draining.
Heat the olive oil over a medium heat. Sauté the onion for 3 minutes until translucent. Add the garlic and sauté for another minute.
Add the tomato purée. Cook for 3-4 minutes, stirring every so often.
Turn the heat to low and add the salt, red chilli flakes and cream. Stir to combine. Add the butter and stir again.
Add 2-3 tablespoons of your reserved pasta water and the cooked pasta. Turn off the heat and stir the pasta to coat it in the sauce.
Serve immediately and top with your burrata. Don't forget to garnish with black pepper, parmesan and basil.