Prince William has told Great British Bake Off runner-up Andrew Smyth that he "should have won" and added he is "going to have a word" with Mary Berry.
The Duke of Cambridge made the comments after being presented with a cake at Rolls-Royce in Derby, where Mr Smyth works as an aerospace engineer.
The rotating cake was made in the shape of a jet engine, and featured fan blades made from gingerbread.
During his visit to Derby, the prince also drove a train at Bombardier.
Mr Smyth chatted to the prince and demonstrated the cake rotating.
William told him: "Ah, you should have won. What's going on? That's amazing.
"I'm going to have a word with Mary [Berry]. You should have won."
The prince was making his first official visit to the city.
While at Bombardier he took control of a test model of one of the trains which will run on Crossrail, including the Elizabeth Line - named after his grandmother the Queen.
'Braking was sharp'
Test train driver Christopher Brittan said the royal driver seemed at ease with the unfamiliar controls.
"He was good - he's a pilot isn't he - so I gave him the basics, and the traction brake controller, but he was good. Controlled," he said.
"We went up to 30mph."
He added: "It was easy, smooth, fast - his braking was sharp. He was very good."
The prince was presented with personalised Rolls-Royce shirts for his children, Prince George and Princess Charlotte.
The prince also met volunteers and clients at the Padley Development Centre for people with complex needs.