Tangzhong:

1. Combine both the milk and bread flour in a small saucepan, and whisk until no lumps remain.
2. Place the saucepan over medium heat and cook the mixture, stirring regularly, until thickened, paste-like, and the spoon or spatula leaves lines on the bottom of the pan. This should take 1 to 3 minutes, depending on the strength of your burner.
3. Remove from the heat and transfer to a large mixing bowl or the bowl of a stand mixer.

Dough:

1. Add the ingredients to the mixing bowl in the order listed; the heat from the tangzhong will help to warm the cold milk.
2. Mix by hand or on low speed of a stand mixer with the dough hook attachment. Continue to knead the dough until it’s smooth, elastic, and tacky. This will take up to 15 minutes by hand and about 10 to 12 minutes on medium-low speed of a mixer.
3. Shape the dough into a ball, place it in a bowl, and cover the bowl with plastic wrap or a reusable cover.
4.  Let the dough rise until puffy but not necessarily doubled in bulk, about 60 to 90 minutes (depending on the warmth of your kitchen).

Filling:

1. While the dough is rising, put the melted butter into a medium bowl and add the remaining ingredients, stirring until the mixture is the texture of damp sand. Set aside.
2. Lightly grease a baking sheet, or line it with parchment paper.

 Assembling the rolls:

1. Transfer the dough to a lightly greased work surface and press it into a 10” x 12” rectangle that’s about 1/2” thick. For evenly shaped rolls, try to pat the dough into an actual rectangle (with corners), rather than an oval.
2. Sprinkle the filling over the dough, covering all but a 1/2” strip along one long side.
3. Starting with the filling-covered long side, roll the dough into a log.
4.  Cut the dough lightly into eight equal 1 1/2” to 2” pieces. (*I like to score with knife first, and then use thread or dental floss to cut, for a clean cut. Cut the dough at the score marks, using dental floss for the cleanest cut
5.  Place the rolls onto the prepared baking sheet, spacing them so there’s at least 2” between each one and they’re 2” away from the edges of the pan; a 3-2-3 arrangement works well. To prevent them from unraveling while they rise and bake, tuck the ends of the spirals underneath the rolls so that they’re held in place.
6.  Cover the rolls with lightly greased plastic wrap or towel and let them rise for 30 to 60 minutes (depending on the warmth of your kitchen). The rolls should be puffy and the dough shouldn’t bounce back immediately when gently pressed.
7.  About 20 minutes before you’re ready to bake, position a rack in the top third of the oven. Preheat the oven to 375°F.
8.  Bake the rolls for 15 to 19  minutes, until they’re a light golden brown. Bake for the lesser amount of time for extra-soft rolls, and the longer amount of time for rolls with a bit more color and slightly firmer texture. (*I bake mine about 18-19 minutes).
9. Remove the rolls from the oven, place the pan on a rack, and brush the hot rolls with 1 1/2 tablespoons of melted butter. Let the rolls cool for 10 minutes before icing.

Frosting:

1. In a medium bowl, beat butter until smooth. Add vanilla, salt, powdered sugar and half & half. Mix until combined and smooth.
2. Frost the rolls and serve immediately. If you’re planning to serve the rolls later, wait to frost them until just before serving. Store frosting at room temperature, tightly covered, until you’re ready to use it.