Complex sentence: Many people now use crouton for croute so the usage has changed, however, historically a croute was a slice of a baguette lightly brushed with oil or clarified butter and baked.
Split into simpler sentences: Many people now use crouton for croute, so the usage has changed. Historically, however, a croute was a slice of a baguette lightly brushed with oil or clarified butter and baked.