Why do you call this cake a Paris-Brest?
Besides the Tour de France, every four years France holds a 1200 kilometers bicycle race that goes from Paris to Brest and back to Paris (commonly known as "PBP").
This race first took place in 1891 and it is the oldest cycling event still being run. The same year that the race began, a pastry chef along the bicycle route decided to make a celebration cake called Paris-Brest, to honor the race.
It consisted of a circle of choux pastry, filled with whipped cream, that was meant to look like a bicycle wheel.
Try it! It's delicious!