A chocolate lover's version of tender milk bread, this dough is highly enriched with sugar, milk, eggs, and butter, which gives the loaf its distinctive feathery crumb. Perfect sliced, made into French toast, or simply toasted and eaten with marmalade and butter, chocolate milk bread is the dessert version of well-loved Japanese milk bread.
To make the tangzhong: In a small saucepan, whisk the cocoas, flour, milk, and water until no lumps remain. Over low heat, bring the mixture to a boil, whisking constantly, until the mixture looks glossy and thickened to the consistency of hot fudge sauce, 3 to 6 minutes. Transfer the tangzhong to the bowl of a stand mixer; it will weigh about 145g after cooking. (If your tangzhong is more than 155g, return it to the pot and cook it a bit longer.)
To make the dough: Add the flour, milk, sugar, milk powder, yeast, salt, butter, and 3 tablespoons (41g) of the beaten egg to the tangzhong in the bowl. Reserve the remaining egg to brush over the loaf before baking.
Using the dough hook, mix on medium-low speed until a soft, sticky dough forms, scraping down the bowl as necessary. Increase the speed to medium-high and continue mixing until the dough almost clears the sides of the bowl (it will stick to the sides for much of the mixing time) and is smooth and elastic, 15 to 20 minutes total. Every few minutes, scrape down the sides and bottom of the bowl, then continue mixing. Eventually the dough will strengthen enough to mostly pull away from the sides of the bowl; the dough will still be slightly sticky but significantly more manageable than it was before kneading. Add the chocolate chips and knead on low speed until fully incorporated, 1 to 2 minutes. (If it’s difficult to incorporate the chocolate chips into the dough using the dough hook, knead them in by hand right in the mixer bowl.) Transfer the dough to a lightly greased bowl, cover, and let it rise until puffy and doubled in bulk, 1 to 1 1/2 hours.
Lightly grease an 8 1/2" x 4 1/2" loaf pan with nonstick spray or vegetable oil.
Use a bowl scraper to gently ease the dough out of the bowl onto a lightly floured work surface. Gently form the dough into a square and divide it into four even pieces (about 160g each).
Flatten each piece of dough by gently pressing and stretching it into a 4" x 6" rectangle, then fold the short ends in toward one another to meet in the center. Flatten each dough piece into a rectangle again (this time about 3" x 5") and, starting with a short end, roll each of them into a log about 3 1/2" long.
Place the logs seam-side down, side by side, in a row of four into the prepared pan. Cover and let the loaf rise until it just crests over the rim of the pan, 45 to 90 minutes, depending on the temperature of your kitchen.
Towards the end of the rising time, preheat the oven to 350°F. Lightly brush the top of the loaf with a thin layer of the remaining beaten egg and sprinkle with sparkling or pearl sugar, if desired. Bake the chocolate milk bread for 30 to 35 minutes, until the loaf is fragrant, the top crust is firm, and the internal temperature is at least 190°F. Remove the loaf from the oven and cool briefly in the pan before turning it out onto a rack to cool completely.
Storage information: Store leftover chocolate milk bread in an airtight container up to 5 days, or freeze for longer storage.
This recipe was developed by metric weight, so for best accuracy we recommend measuring by weight.
Black cocoa gives this loaf a much darker color and more chocolatey flavor, though you can use all Dutch-process cocoa if you don’t have it.
Developing enough structure in the dough is critical to both shaping and achieving a high-rising loaf, so a mixer is essential for this bread.
