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

Cook over medium heat, whisking constantly, until the mixture thickens to pudding consistency, about 2-3 minutes.

Transfer to a bowl and cool to room temperature before using.

In a large bowl or stand mixer, whisk together flour, instant-yeast, sugar, salt, orange zest, and cardamom.

Add the cooled tangzhong, eggs, milk, and honey. Mix on low speed until a shaggy-mass forms.

With the mixer running on medium-low, add the cold butter cubes a few at a time. This takes 5-7 minutes.

Continue mixing for another 3-4 minutes until the dough is smooth, elastic, and pulls away from the sides of the bowl.

Transfer to a lightly greased bowl, cover tightly with plastic wrap, and refrigerate overnight (8-24 hours).

Roll the cold dough to a 20 x 14 inch rectangle using a rolling-pin.

Spread filling leaving a 1-inch border on all sides, especially on the sealing edge.

Roll from the long side into a tight log, pinching the seam firmly to seal.

Connect ends to form an oval ring, pinching firmly. Place seam side down.

Cut every 2 inches, about halfway through the dough.

Place rack in center of oven. Preheat to 350°F (175°C).

Bake 25-30 minutes until golden brown on top and internal temperature reaches 190°F.

Immediately brush hot cake with heavy cream to lock in moisture.

Let cool on wire rack for at least 1 hour before icing.