Whisk bread flour and milk in a small saucepan until no lumps remain.

Place over medium-low heat, stirring constantly with a spatula or whisk.

Continue stirring until mixture thickens to a mashed potato consistency and reaches 150°F (65°C). You'll see lines form when you drag your spatula through.

Remove from heat immediately. Stir in cold butter until completely melted and incorporated.

Transfer to a bowl. Press plastic wrap directly onto surface to prevent skin. Cool to room temperature (or refrigerate if making ahead).

In the bowl of a stand mixer, add warm milk, honey, and cooled tangzhong. Stir with a spatula to combine.

Add bread flour, milk powder, salt, and instant yeast. (Keep salt and yeast on opposite sides of the bowl.)

Using the dough hook, mix on low speed for 2 minutes until a shaggy dough forms.

With mixer running on low, add the whole egg and egg yolk. Increase to medium-low and mix for 3 minutes.

Add softened butter in 3 additions, waiting until each is mostly incorporated before adding the next. This takes patience—don't rush it.

Increase to medium speed and knead for 8-10 minutes. Dough should be smooth, elastic, slightly tacky, and clear the sides of the bowl.

Pinch off a small piece and stretch it thin. If you can stretch it until light passes through without tearing, you're done.

Shape dough into a ball and place in a lightly greased large bowl.

Cover tightly with plastic wrap or a damp towel.

Let rise at room temperature (75-78°F / 24-26°C) until doubled in size, about 1-1.5 hours.

Press a floured finger ½ inch into dough. If the indent springs back slowly but remains visible, it's ready.

Gently transfer dough to a lightly floured surface. Don't punch it down aggressively—just deflate gently.

Use a bench scraper to divide into 10 equal pieces. For consistency, weigh each piece (90-95g each).

Gently shape each piece into a ball by tucking the edges underneath and pinching to seal.

Cover loosely with a towel. Let rest 10 minutes to relax the gluten.

Select either the free-form method for sheet pan baking, or the New England pan method for classic top-split buns.

Loosely cover the shaped buns with plastic wrap or a damp towel.

Let rise at room temperature until puffy and nearly doubled, 45-60 minutes.

Gently poke a bun—it should feel airy and spring back slowly.

Start preheating your oven to 375°F (190°C) about 20 minutes before baking.

Beat 1 egg with 1 Tbsp milk. Gently brush over proofed buns.

Sprinkle with sesame seeds, poppy seeds, or Everything Bagel seasoning.

Place in preheated 375°F oven. Bake for 15-18 minutes until deep golden brown.

Internal temperature should reach 190°F (88°C).

Immediately brush hot buns with melted butter. This is what keeps the crust soft.

Transfer to a wire rack. Cool at least 15 minutes before slicing.

Use a serrated knife to cut horizontally through the top (or side for regular buns), leaving about ½ inch connected at the bottom.

Working with one ball at a time, use your palms or a rolling pin to flatten into a 4" x 6" rectangle.

Starting from the long edge (6" side), roll the dough tightly toward you, keeping tension.

Pinch the seam closed. Pinch the ends closed and tuck slightly underneath.

Gently roll with your palms to create an even 6-inch log.

Place seam-side down on a parchment-lined sheet pan. Arrange in 2 rows of 5, with buns touching side-by-side (about ½ inch apart before proofing).

Follow steps 1-4 from Free-Form method for each piece.

Arrange shaped logs in the greased pan cavities.

Instead of individual logs, stretch the entire dough mass into a 15" x 6" rectangle and press into the pan, pushing into corners.