Its ring shape is meant to evoke a bicycle wheel, and the pastry was commissioned to honour a race in which riders cycled from Paris to Brest and back, about 1,200 km.
Paris-Brest is a ring of choux pastry sliced open and filled with hazelnut-praline cream, topped with sliced almonds and powdered sugar. Pastry shops across Paris sell it whole or as individual rings from the counter.