Add the milk, egg, sugar, salt, and instant yeast to the Ooni Halo Core mixer bowl. Stir to combine, then add the melted, cooled butter and bread flour.

Fit the spiral dough hook and breaker bar. Mix at a low setting until no dry flour remains, then increase the speed as appropriate for your mixer and knead until smooth and elastic.

Transfer the dough to a lightly greased container. Prepare the Folding Proofer with its rack and water tray according to the manufacturer’s instructions.

Proof at 26–28°C / 79–82°F for about 1½ hours, until approximately doubled.

Cut the salted butter into eight 10 g pieces. Refrigerate until needed.

Beat the softened butter and sugar until smooth. Gradually mix in the beaten egg, scraping down the bowl as needed.

Stir in the cinnamon and cooled water. Add the cake flour and mix just until smooth. Transfer to a piping bag.

Gently press the risen dough to release the gas. Weigh and divide into eight equal portions, approximately 74 g each.

Flatten each ball into a small disk. Place one cold butter portion in the center, bring the dough around it, and pinch the seams firmly closed.

Proof in the Folding Proofer at 26–27°C / 79–81°F for about one hour, keeping the setting below 28°C / 82°F.

Toward the end of proofing, preheat the oven to 180°C / 350°F.

Snip the piping bag to make a small opening. Starting in the center of each bun, pipe a close spiral over the dome, covering approximately the upper two-thirds.

Bake for approximately 20-24 minutes, until the topping is set and crisp and the exposed bread is golden. Let the buns cool on the tray briefly, then transfer to a rack.