Here’s a standard brioche dough that will make twelve 1.6-ounce brioche à têtes, one single loaf, or a batch of cinnamon (a.k.a. “sticky”) buns. Start by putting into a bowl:
2 tablespoons milk
1 tablespoon sugar
1/4 teaspoon instant yeast
3 ounces all-purpose flour
Stir all of it together withe a fork until the mixture is the consistency of a thick batter.
This is your sponge. Scrape it into the bowl of an electric mixer (for best flavor, let it ferment for an hour, refrigerate it overnight, and then scrape it into a mixer bowl when you want to make your dough).
When ready to make the dough, whisk together a mixture of:
6 ounces all-purpose flour
2 tablespoons sugar
1 1/4 teaspoons instant yeast
1/2 teaspoon salt
…and sprinkle over the sponge in the mixer bowl.
Let it sit for 2 hours, 2 1/2 – 3 if the sponge was refrigerated. The dome of dry mix will crack as the sponge expands. It may even bubble through in a few spots. This is good.
To mix, add two cold eggs and using the dough hook, beat the mixture for 2-3 minutes on medium speed.
When it gets to looking like so…
…start adding your butter. With the machine running, begin to add 4 ounces of very soft butter. Add it a tablespoon at a time, letting the dough absorb each addition before adding another.
Notice how light and sticky it gets:
Once the dough is uniform (and it might take an extra bowl scraping or two), scrape it into a oiled bowl or rising container.
Let it rise another 1 1/2 hours until it looks about like so:
Drape a piece of plastic wrap over it and deflate it by gently pressing down on it with your hand.
Put it into the refrigerator, letting it chill for a minimum of two hours, preferably overnight, to firm it (you’ll likely need to deflate it one more time after the first hour or so). It will keep for up to three days in the fridge and can be frozen for several months.