I do not envision that Mr Chaucer was a 14th Century Gordon Ramsay. It seems reasonable, therefore, to deduce that Mrs Chaucer was cooking the pie and Mr Chaucer was writing down the recipe so that it could be repeated to others.
It also seems logical that Mrs Chaucer was not the first person to think of putting apples and other fruits into a pie. Mrs Chaucer could have been making pies with only apples in them since 1380 but when she decided to add other fruits, Mr Chaucer thought that was interesting enough to write down. Persons unknown could have been making apple pie for years or hundreds of years but none of those people were capable of writing or the documents did not survive.
You may have heard of two crusty old tomes called the Old Testament and the New Testament. Neither was contemporaneous to the events that they claim to portray. They may not have been the first ones written but they are the surviving ones. Their factual accuracy is easily questioned as there is no proof of any of the events but there always seems to be a ready supply of people easily brainwashed to keep religion going without questioning. In two millennia, will people worship Harry Potter for his wizardry? Technological advancement suggests probably not.
