Question: What is "confarreatio"?
About the article "Cake", section "Special-purpose cakes".

Candidate passages:
The ritual of confarreatio was one way of obtaining cum manu marriage, limited to the practice of patricians.
This is a particular kind of sacrifice made to Jupiter.
During this ritual the bridegroom and bride shared a bread made of "farreus" known as emmer grain, hence confarreatio translates to “sharing of emmer bread.” This process required the presence of ten witnesses and the recital of ceremonial sacred verses.
High priests such as the priests of Jupiter, Mars, and Quirinus were required to be born from confarreatio union and were otherwise unqualified to obtain priesthood.
As confarreatio slowly fell from favor it became difficult to find candidates for priesthood.
In order to revive confarreatio marriages, the practice endured some amendments.
Consequently, the "flamen Dialis’s" wife only fell under the control of her husband during rituals, and was otherwise as autonomous as other women.
Cum manu was no longer acquired by the employment of confarretio and became restricted to patricians pursuing in priestly positions. 
In ancient Rome, confarreatio was a traditional patrician form of marriage.
The ceremony involved the bride and bridegroom sharing a cake of spelt, in Latin "far" or "panis farreus", hence the rite's name.
The Flamen Dialis and Pontifex Maximus presided over the wedding, and ten witnesses had to be present.
The woman passed directly from the hand "(manus)" of her father or head of household (the "paterfamilias") to that of her new husband.
Having parents who were married by "confarreatio" was a prerequisite for becoming a Vestal or the Flamen Dialis.
"Confarreatio" seems to have been limited to those whose parents were also married by "confarreatio", but later, perhaps with the rise of plebeian "nobiles", this requirement must have been relaxed.
Scipio Africanus presumably married his wife Aemilia Tertia by "confarreatio", because their elder son was Flamen Dialis; yet Scipio's mother Pomponia was a plebeian.
Likewise, Julius Caesar married Cornelia by "confarreatio", but neither had patrician mothers, and Caesar's parents had not married by "confarreatio".
Divorce for "confarreatio" marriages, "diffarreatio", was a difficult process and therefore rare.
Not much is known about how "diffarreatio" was carried out except that there was a special type of sacrifice that caused the dissolution of the relationship between the man and woman.
She would then pass back into the "manus" of her "paterfamilias".
Originally, the "confarreatio" was indissoluble, and this remained true of the marriage of the Flamen Dialis.
The other two major flamens, the Flamen Martialis and the Flamen Quirinalis, were also required to marry by "confarreatio."
The three major flamens were also required to marry virgins; further, if the wife of the Flamen Dialis died, he was immediately required to resign.
It is not clear if this was true of the other priests. 
It was used during the pagan celebrations of the return of the Spring time.
During these celebrations Ceres’ priestess brought an egg, symbol of new life in procession.
Because of the wheat or the einkorn, mixed with the soft ricotta cheese, it could come from the einkorn bread called "confarreatio", an essential ingredient in the ceremony of the type of ancient Roman weddings named after it "confarreatio".
Another hypothesis we may consider is that it comes from ritual bread used, which spread during the period of Constantine the Great.
They were made of honey and milk the people offered the catechumen during Easter Eve at the end of the ceremony of baptism. 
In ancient Roman religion, the Flamen Martialis was the high priest of the official state cult of Mars, the god of war.
He was one of the "flamines maiores", the three high priests who were the most important of the fifteen flamens.
The Flamen Martialis would have led public rites on the days sacred to Mars.
Among his duties was the ritual brandishing of the sacred spears of Mars when the Roman army was preparing for war.
Like other "flamines maiores", the high priest of Mars was a patrician and required to marry through the ceremony of "confarreatio".
It is not clear whether the death of his wife required him to resign his duties, as was the case for the Flamen Dialis. 
Office holders in the city of Rome.
Marcus Antonius.
In his function as "pontifex maximus" Julius Caesar himself chose Mark Antony for the office using the ritual of "captio".
He couldn't designate his nephew Gaius Octavius, because he had already planned for him to become his political heir.
But Mark Antony was equally suited for the office, because he was a close confidant of Caesar and a near relative through his mother Iulia.
In addition he had been "augur" since 50 BC and later "magister" of the newly established "luperci Iulii".
He hadn't exercised a political office since 47 BC, when he assumed "consulship" in 44 BC together with the "dictator perpetuo".
Following Caesar's "captio" Mark Antony was at first unable to inaugurate, because he was a plebeian.
On the basis of the "lex Cassia" of 45 BC Caesar however had the right to elevate him (and Gaius Octavius) to patrician status.
The fact that Marc Antony's parents hadn't been wedded with the ancient ritual of the "confarreatio" was obviously ignored in this case.
Furthermore, a "destinatus" for the office of a "flamen maior" needed to be eventually married by "confarreatio" himself, a requirement which Marc Antony was unable to meet at first.
After Caesar's death the situation provoked malicious remarks by the anti-Caesarian fraction and forced Caesar's political heir Octavian into action.
But only after the successful peace negotiations at Brundisium in October 40 BC was Mark Antony able to inaugurate as "flamen Divi Iulii" at the request of the other two triumvirs, because by then Antony's plebeian wife Fulvia had died and his new wife Octavia, sister of Octavian, had been lawfully wedded to him by "confarreatio".
Due to the transient peace between Mark Antony and Octavian, Antony eventually lost his flaminical influence in the western part of the Roman empire in 33 BC and only maintained rule in the Hellenistic east, where his policies surely included the supervision of the Julian religion until his defeat in the battle of Actium 31 BC and subsequent death in Egypt in the following year.
Whether the flaminical vacancy in western Rome was unofficially occupied by Octavian is unknown, but feasible, since he had always overseen parts of his divine father's cult in Rome.