Agreed, the accepted translation(s) is/are just wrong, and the correct translation(s) are rejected. Even for Duolingo, I think that's a first, or at least the most blatantly absurd. Hopefully this'll get fixed soon!
Yes, Duo did not accept my answer "I am going to make you a dessert that I am proud of", and said the correct response would be "I'm going to make a dessert that I'm proud of." (omitting the 'you')!!! Reported of course... Many of these new lessons have bugs.