https://en.wikipedia.org/wiki/Brioche
Brioche (/ˈbriːoʊʃ, -ɒʃ/; French: [bʁi.ɔʃ]) is a pastry of French origin that is similar to a highly enriched bread, and whose high egg and butter content (400 grams for each kilogram of flour) give it a rich and tender crumb. Chef Joel Robuchon describes it as "light and slightly puffy, more or less fine, according to the proportion of butter and eggs."[1] It has a dark, golden, and flaky crust, frequently accentuated by an egg wash applied after proofing.
Brioche is considered a Viennoiserie, in that it is made in the same basic way as bread,
but has the richer aspect of a pastry because of the extra addition of eggs, butter, liquid (milk, water, cream, and, sometimes, brandy) and occasionally a bit of sugar. Brioche, along with pain au lait and pain aux raisins—which are commonly eaten at breakfast or as a snack—form a leavened subgroup of Viennoiserie. Brioche is often cooked with fruit or chocolate chips and served on its own, or as the basis of a dessert with many local variations in added ingredients, fillings or toppings.