Instructions

• Warm 2/3 cup milk to 105–115°F (warm to the touch, not hot). Pour the warm milk into a small bowl, sprinkle the package of dry active yeast over the surface, stir in the 1/3 cup sugar, and let sit 5–10 minutes until foamy. If the mixture does not become foamy, the yeast may be inactive—discard and start with fresh yeast.
• While the yeast proofs, melt the 1/3 cup butter and let it cool until warm (not hot).
• In the bowl of a stand mixer, whisk together the 1/4 teaspoon salt and 2/3 cup of the flour (reserve the rest of the flour for later).
• Add the foamy yeast-milk mixture, the warm melted butter, and 1 whole egg to the mixer bowl. Mix on low speed just until the wet ingredients are combined with the dry.
• Fit the mixer with a dough hook. With the mixer running on low, add the remaining flour gradually—about 2 to 2 1/3 cups total—adding 1/4 cup at a time until a soft, slightly sticky dough forms. Use the lower amount of flour first and add more only if the dough is too sticky to handle.
• Knead the dough in the mixer on medium-low speed with the dough hook for 5–7 minutes, until the dough is smooth, elastic, and pulls away from the sides of the bowl but remains slightly tacky.
• Transfer the dough to a lightly greased bowl, turn once to coat the top, cover with plastic wrap or a clean kitchen towel, and let rise in a warm, draft-free place until doubled in size, about 1 to 1 1/2 hours.
• Punch the risen dough down, turn it out onto a lightly floured surface, and roll it into a rectangle suitable for braiding (a roughly 12 x 8–10 inch rectangle works well).
• To form a braid: trim the short ends so they are straight, then cut 1-inch-wide strips along both long sides of the rectangle, leaving a center panel about 3–4 inches wide. The center panel will remain flat while you braid the side strips over it.
• Fold the strips over the center panel alternately from each side to form a braid, overlapping each strip about halfway across the center. Tuck the ends under to finish and transfer the braided dough to a parchment-lined baking sheet. Cover loosely and let rise 20–30 minutes until puffy.
• Preheat the oven to 375°F. Meanwhile, make the egg wash by whisking together the reserved 1 egg yolk and the 1 teaspoon water.
• Brush the braided dough with the egg-yolk wash, then bake in the preheated oven 18–22 minutes, or until the braid is golden brown and cooked through. Remove from the oven and cool on a wire rack before serving.