Definition of "gâteau"

We were served pancakes with smoked salmon, followed by thick slices of gâteau.

1993, Christopher Evans, Aztec Century, London: Gollancz, published 2013

Julie was a froster, the glamour job at the factory. She wore her cute white hat cocked at a jaunty angle while working a big white bag of frosting, twisting it rapidly in her hands to create the various designs on top of the gâteaux.

2016, Martha Grimes, Ken Grimes, Double Double: A Dual Memoir of Alcoholism, page 88