In a clean jar, combine the active starter, bread flour, lukewarm milk, and sugar. Stir until well combined — the mixture will be stiff. Close the lid loosely and leave at room temperature (75–78°F / 24–26°C).

The levain is ready when it has doubled or more in size, is domed on top, and has visible bubbles throughout. This takes 8–10 hours at 75–78°F. A levain built with milk moves a little slower than one built with water — that's normal.

Combine currants and candied orange peel in a bowl. Pour the hot tea or orange juice over them. Cover and let soak at least 30 minutes. Drain well before using.

Whisk 25g bread flour and 125g whole milk in a small saucepan until smooth. Heat over medium-low, stirring constantly, until the mixture thickens to a paste and reaches 65°C (149°F) — about 3–4 minutes. Press plastic wrap directly onto the surface and cool completely.

In your stand mixer bowl, whisk together the bread flour, sugar, salt, cinnamon, allspice, nutmeg, cardamom, and orange zest.

Add the lukewarm milk, eggs, cooled tangzhong, and all of the sweet levain. Mix on low with the dough hook for 2–3 minutes until a shaggy dough forms.

Add softened butter in small pieces with the mixer running on low. Once incorporated, increase to medium-low and knead for 8–10 minutes until smooth and elastic. By hand: 12–14 minutes.

Add the drained soaked fruit and mix on low for 2 minutes until evenly distributed. Don't overwork.

Shape the dough into a ball, place in a lightly greased bowl, and cover with plastic wrap. Ferment at room temperature (75–78°F / 24–26°C) overnight, about 8–12 hours, until the dough has approximately doubled.

The dough is ready when it's noticeably puffed, slightly jiggly when you shake the bowl, and a floured finger pressed in springs back slowly. If it springs back immediately, give it more time. If the indent stays, move on — it's at or past peak.

Punch down the dough gently and turn out onto a lightly floured surface. Weigh the total dough and divide by 12. Each bun should be approximately 85–90g.

Pull the edges toward the center, rotating as you go, to build surface tension. Flip seam-side down. Cup your hand and roll in a tight circle on the surface until smooth and taut.

Place shaped buns in the greased 9×13 pan in a 3×4 grid with about ½ inch of space between each bun.

Cover the pan loosely and let proof at room temperature (75–78°F) for 2–3 hours until the buns are visibly puffed, touching their neighbors, and spring back slowly when gently pressed.

20 minutes before the end of the proof, preheat your oven to 400°F (200°C).

Whisk together the bread flour, water, and sugar until completely smooth. The paste should be thick enough to hold its shape when piped — like a stiff toothpaste. Adjust water by the teaspoon if needed.

Transfer paste to a piping bag or zip-lock bag with a small corner snipped. Pipe one continuous line across each row of buns, then rotate 90 degrees and pipe across the columns. Pipe slightly thinner than you want — they spread a little in the oven.

Brush exposed dough (not the paste) with egg wash.

Bake at 400°F (200°C) for 20–25 minutes until deep golden brown. Internal temperature should reach 190°F (88°C).

While the buns bake, combine the apricot jam (or orange marmalade) and water in a small saucepan over medium heat. Stir until smooth and runny.

Brush generously over the entire surface the moment the buns come out of the oven. Let cool in the pan for 10–15 minutes before pulling apart.