To make the tangzhong: Combine all the starter ingredients in a small saucepan, and whisk until no lumps remain.

Place the saucepan over medium heat, and cook the mixture, whisking constantly, until thick and the whisk leaves lines on the bottom of the pan. This will probably take only a minute or so.

Remove from the heat, and set aside for several minutes.

To make the dough: Mix the tangzhong with the remaining dough ingredients in mixer bowl until everything comes together. Let the dough rest, covered, for 20 minutes; this will give the flour a chance to absorb the liquid, making it easier to knead.

After 20 minutes, knead the dough to make a smooth, elastic, somewhat sticky dough (6-7minutes with mixer and 1 minute by hand).

Shape the dough into a ball, and let it rest in a lightly greased covered bowl for 60 to 90 minutes, until puffy but not necessarily doubled in bulk.

To make the filling: Combine the brown sugar and cinnamon, mixing until the cinnamon is thoroughly distributed.

Gently deflate the risen dough, leave it whole for larger buns or divide it in half for smaller. Roll dough into 18” x 8” rectangle.

Sprinkle the filling on single piece (for large buns) or half on each piece (for smaller buns).

Starting with a long edge, roll the dough into a log. With the seam underneath, cut the log into 12 slices, 1 1/2” each. Repeat with second piece if making smaller buns.

Lightly grease a 9” x 13” pan. Space the rolls in the pan.

Cover the pan and let rise for 45 to 60 minutes, until they’re crowding one another and are quite puffy.

While rolls are rising, preheat oven to 350 degreeF with rack in the bottom third.

Uncover the rolls , and bake them for 22-25 minutes, until they feel set. They might be just barley browned, that’s OK. It’s better to under-bake these rolls than to bake them to long. The interior temperature should be about 188 degreesF.

While the rolls are baking, stir together the icing ingredients, adding enough milk to make a thick spreadable icing. The icing should be quite stiff, about the consistency of softened cream cheese.

Remove the rolls from the oven, and turn them out of the pan onto a rack. Spread them with icing; it’ll partially melt into the rolls.

Serve the rolls warm. Store completely cool rolls for a couple of days at room temperature, or freeze for up to 1 month.

Tip: For just-baked freshness, reheat rolls by tenting with aluminum foil and heating in a 350 degreeF oven until toasty warm.