Directions
<ol class="no-list-style"><li class="MethodStepper"><h4 class="step-title">Step 1</h4>Start by making the tangzhong (water roux starter). In a small saucepan, whisk together 30g bread flour and 150ml milk until smooth. Heat over medium-low heat, stirring constantly until the mixture thickens to a paste-like consistency that holds a line when you draw your spoon through it (about 65°C if you have a thermometer). This usually takes 3-5 minutes. Transfer to a small bowl, cover with plastic wrap directly on the surface to prevent a skin from forming, and let cool to room temperature. The tangzhong is the secret to exceptionally soft, fluffy bread that stays fresh longer.</li><li class="MethodStepper"><h4 class="step-title">Step 2</h4>While the tangzhong cools, prepare the black sesame filling. Toast the black sesame seeds in a dry pan over medium heat for 3-4 minutes until fragrant, shaking the pan frequently to prevent burning. Let cool slightly, then grind in a food processor or spice grinder until fine but not completely turned into paste. Mix the ground sesame seeds with the softened butter, sugar, and a pinch of salt until well combined. Set aside at room temperature so it remains spreadable.</li><li class="MethodStepper"><h4 class="step-title">Step 3</h4>For the bread dough, combine the bread flour, sugar, yeast, and salt in the bowl of your stand mixer. In a separate bowl, whisk together the cooled tangzhong, warm milk, and egg until well combined. With the mixer on low speed using the dough hook, gradually pour the wet ingredients into the dry ingredients. Mix until just combined, about 2 minutes.</li><li class="MethodStepper"><h4 class="step-title">Step 4</h4>Add the softened butter to the dough, one tablespoon at a time, waiting until each addition is incorporated before adding more. Once all butter is added, increase the speed to medium and knead for 8-10 minutes until the dough is smooth, elastic, and passes the windowpane test (when a small piece can be stretched thin enough to see light through without tearing). The dough will be slightly tacky but should clear the sides of the bowl.</li><li class="MethodStepper"><h4 class="step-title">Step 5</h4>Transfer the dough to a lightly greased bowl, cover with plastic wrap or a damp kitchen towel, and let rise in a warm place until doubled in size, about 1-1.5 hours. The ideal temperature for proofing is around 24-27°C. If your kitchen is cool, you can create a warm environment by placing the bowl in an oven with just the light turned on.</li><li class="MethodStepper"><h4 class="step-title">Step 6</h4>Once doubled, gently punch down the dough to release air bubbles and transfer to a lightly floured surface. Divide the dough into 9 equal pieces (use a scale for precision). Shape each piece into a ball, cover with a kitchen towel, and let rest for 15 minutes to relax the gluten.</li><li class="MethodStepper"><h4 class="step-title">Step 7</h4>Working with one dough ball at a time (keeping others covered), roll out into a rectangle about 15x10cm. Spread about 1-1.5 tablespoons of the black sesame filling evenly over the dough, leaving a 1cm border around the edges. Starting from the long side, roll up the dough tightly like a Swiss roll. Pinch the seam to seal, and place the roll seam-side down in a greased 23cm square baking pan. Repeat with remaining dough pieces, arranging them in 3 rows of 3 in the pan.</li><li class="MethodStepper"><h4 class="step-title">Step 8</h4>Cover the pan with a kitchen towel and let the rolls proof again until puffy and nearly doubled in size, about 40-60 minutes. They should be touching each other slightly when ready. During the final 20 minutes of proofing, preheat your oven to 180°C.</li><li class="MethodStepper"><h4 class="step-title">Step 9</h4>When the rolls have finished their second rise, gently brush the tops with milk and sprinkle with the mixed black and white sesame seeds. Bake in the preheated oven for 22-25 minutes until golden brown and a thermometer inserted into the center registers 90°C. If the tops brown too quickly, loosely cover with aluminum foil.</li><li class="MethodStepper"><h4 class="step-title">Step 10</h4>Remove the pan from the oven and let the rolls cool in the pan for 10 minutes before transferring to a wire rack. These rolls are best enjoyed warm, when the texture is at its cloudlike softness and the black sesame filling is still slightly warm. Store any leftovers in an airtight container for up to 3 days, or freeze for longer storage. To reheat, warm in a 160°C oven for 5-7 minutes or microwave individual rolls for 15-20 seconds.</li></ol>