Of the holidays I grew up with, the one that seems it'd be the most inherently celebratory is the Epiphany:

1. A manifestation or appearance of a divine or superhuman being.
2. An illuminating realization, often resulting in a personal feeling of elation, awe, or wonder.

(from ancient Greek ἐπιφάνεια, meaning "manifestation" or "striking appearance",
from the proto-Indo-European root bhā-, meaning "to shine")

The Epiphany was the day when we would find small gifts brought by la Befana, a generous, kindly old Italian witch who drops in the night before. La Befana is said to have helped the three astrologer-kings on their way to baby Jesus: for Roman Catholics, the Epiphany is a celebration of their arrival and their gifts of gold, Frankincense, and myrrh. However, it is likely la Befana comes from a pre-Christian tradition. From the book Vestiges of Ancient Manners and Customs, Discoverable in Modern Italy and Sicily:

This Befana appears to be heir at law of a certain goddess called Strenia, who presided over the new-year's gifts, 'strenae,' from which, indeed, she derived her name. Her presents were of the same description as those of the Befana - figs, dates, and honey. Moreover her solemnities were vigorously opposed by the early Christians on account of their noisy, riotous, and licentious character.

Alternative names for the feast in Greek include hē Hēméra tōn Phṓtōn, "The Day of the Lights", and ta Fóta, "The Lights".

The galette de rois or king cake is the traditional cake served on the Feast of the Epiphany in French-speaking areas. It too stems from an older Roman tradition, the festival of Saturnalia. The Romans considered it to be a week of liberty and revelry for all (...even eventually replacing human sacrifices with ritual sacrifices of masks) - Saturn was said to have reigned in the Golden Age, when humans enjoyed the wild abundance of the Earth without the constraints of social distinctions. Slaves joined their masters for feasts, during which cake was served. One of the pieces of cake had a bean hidden in it, and whoever received it became the "Prince of Saturnalia". The prince was the ruler of this chaotic and absurd party: he could institute outlandish rules and commands which had to be followed, and disrespect anyone without fear of punishment. Romans also gave each other gifts, often pottery figurines called sigillaria or rather silly gifts of low monetary value. The beginnings of the galette de rois, which involved the cruel and supremacist practice of slavery in Roman society, transformed to reflect different values and powerful institutions that came to prominence in Europe.

For instance, the tradition has survived several Christian attempts to eradicate it entirely, for the most part by being subsumed under the Christian celebration of the arrival of the three Magi. The cake was also almost banned during the French Revolution- instead its name was (temporarily) changed to "la galette de l'Égalité" and the bean (la fève) removed. The cake itself is made of layers of puff pastry filled with almond paste, and these days a small trinket is often used instead of a bean. The youngest person hides under the table and points to whoever should receive the next piece of cake. Whoever finds la fève wears a (paper) crown that evening. These current traditions draw me to the potential of Epiphany themes when they embody playfulness and generosity: our selves manifesting the divine, the spontaneous rise of surreal order and gift-giving.

Yet, Epiphany mostly felt like a bookend to the Christmas season in my family. This has changed quickly through the generations: my nonna told me that when she was a child, the cultural importance of Epiphany was similar to Christmas and that the children were even more excited for Epiphany. There was no Babbo Natale who came on Christmas - instead, for Epiphany, la Befana would leave tangerines, almonds, and walnuts for the children, and all of my nonna's cousins would come over to eat chocolates and dance.

To bring the festival of Epiphany into its full force (which perhaps would be to generate profound realizations), we iterated on its traditions to offer a generative procedure for a new epiphany celebration with wild generosity at its core. Rather than choose a single king, everyone plays a specific being based on the fève they uncover. Just as the Prince of Saturnalia is endowed with the power to create his absurd kingdom, each being has a gift that they bring to shape the experience of the group. The beings, along with their fèves, gifts and regalia, are created by those attending the meal.

with love, M
Note: some of this short history is drawn directly from the linked Wikipedia pages