All of the Magic Tree House Books were written by Mary Pope Osborne.
she wrote the magic tree house books
Thomas Mann wrote The Magic Mountain.
Sarah Prineas wrote The Magic Thief.
Howard Fast wrote April Morning.
John B. Sebastian from the Lovin' Spoonful wrote Do You Belive In Magic.
If you mean in the Harry Potter books, Bathilda Bagshot wrote a History of Magic.
Pilot
Australian writer and artist Norman Lindsay (1879-1969) wrote The Magic Pudding.
The Magic Finger was written by Roald Dahl.
The Magic Faraway Tree
Maya Angelou wrote "On the Pulse of the Morning", She delivered it on the inauguration of President Clinton in 1993.
Mark Stone