Author of The Bread Collection and Bake from Scratch magazine editor-in-chief Brian Hart Hoffman has some words of advice for this recipe: "Mixing really matters. Proper mixing is what gives brioche its soft, feathery finish. Be sure to let every pat of butter fully incorporate before adding more (step 4 in Basic Brioche Dough). Don't rush it." Speaking of rushing, start this before you go to bed one night, as you'll want to let the dough rest for at least 8 hours. Once you've done that, though, the process is smooth sailing.
Yield: One 9- by 5-inch loaf
Prep Time: 30 minutes, plus overnight proofing
Cook Time: 55 minutes
Total Time: 1 hour and 25 minutes, plus overnight proofing
For the Basic Brioche Dough:
⅓ cup (80 grams) warm whole milk (80ºF to 100ºF)
¼ cup (50 grams) granulated sugar
1 tablespoon (9 grams) active dry yeast
3¼ cups (406 grams) all-purpose flour, divided
5 large eggs (250 grams), room temperature
1 teaspoon (3 grams) kosher salt
1 cup (227 grams) unsalted butter, softened
For the Chocolate Brioche:
Basic Brioche Dough
¾ cup (128 grams) chopped 64% cacao dark chocolate
1 large egg (50 grams), lightly beaten
1. Make the Basic Brioche Dough: In the bowl of a stand mixer fitted with the paddle attachment, combine warm milk, sugar, and yeast. Let stand until mixture is foamy, about 10 minutes.
2. With mixer on medium-low speed, add 1½ cups (188 grams) flour and eggs, beating until smooth, 2 to 3 minutes. Cover and let stand for 30 to 45 minutes.
3. Switch to the dough hook attachment. Add salt and remaining 1¾ cups (18 grams) flour, and beat at medium speed until a smooth and elastic dough forms and pulls away from sides of bowl, 8 to 10 minutes.
4. With mixer on medium speed, add butter, 1 tablespoon (14 grams) at a time, letting each piece incorporate before adding the next.
5. Spray a large bowl with cooking spray. Place dough in bowl, turning to grease top. Cover and let rise in a warm, draft-free place (75ºF) until doubled in size, 1½ to 2½ hours.
6. On a lightly floured surface, turn out dough, and fold a few times to knock out a bit of air. Return dough to greased bowl; cover and refrigerate for at least 8 hours or overnight.
7. Make the chocolate brioche: Butter and flour a 9- by 5-inch loaf pan. On a lightly floured surface, turn out Basic Brioche Dough. Punch down dough, and sprinkle chocolate onto dough. Knead chocolate into dough briefly, just until chocolate is incorporated.
8. Shape dough into a loaf. Place dough, seam side down, in prepared pan. Cover and let rise in a warm, draft-free place (75ºF) until dough is puffed, 30 to 40 minutes.
9. Preheat oven to 400ºF. Brush top of loaf with egg wash, and bake for 15 minutes. Reduce oven temperature to 350ºF, and bake until golden brown and an instant-read thermometer inserted in center registers 190ºF, 35 to 40 minutes more. Let cool and serve.