That law of 1790 DID include as natural born citizens those whose fathers were citizens and whose mothers were not. More importantly, it says that CONGRESS was in charge of the decision, and constitutionally so.
And you know who was president 3 years after the ratification of our Constitution and who signed that law of 1790?
So Sorry, even under your position... neither Cruz nor Obummer are natural Born citizens because both their fathers were NOT citizens at the time they were born.