Egg matzah, matzah made using fruit juice instead of water, chocolate matzah, and other enriched matzah made with other ingredients beside matzah flour and water in the traditional way, cannot be used to fulfil the mitzvah of matzah.  Furthermore they are customarily not eaten during Pesach by Askenazi Jews even when bearing a reputable "Kosher for Passover" endorsement.  This is because there is a concern that if the juice used has water in it, the mixture will make the matzah chametz.  This restriction does not apply to the elderly, sick or infants.  Sephardim should consult their rabbi