Preheat the oven to 450°F with a rack in the lower middle position.
Press a large piece of parchment into one loaf pan, bending the corners in and pleating the edges so it takes the shape of the pan. Lift it out and set it aside.
Cut three pieces of butcher's twine, each long enough to wrap under the loaf and tie at the top with a few inches to spare. If you like, grease them lightly with oil or butter as insurance against sticking. Cut six thin strips of parchment for tucking under the strings.
With the cold dough still in the banneton, lay a piece of parchment over it. Lay the three strings across the parchment so they cross in the center like the spokes of a wheel, marking out six even sections, then lay the parchment you shaped in the pan over the strings.
Place one hand on top of the parchment and the other under the banneton, flip it over onto the counter in one quick motion, and lift off the banneton. The loaf is now top side up on the shaped parchment with the strings underneath.
Score a few short cuts around the base of the loaf.
Lift the loaf by the shaped parchment and lower it into the loaf pan.
With the loaf in the pan, bring the strings up around it, keeping the sections even, and tie them together at the center of the top. Tie them snug enough to define each section but loose enough that they only gently hug the dough. Trim the ends.
Tuck a thin strip of parchment between each of the six string lines and the dough.
Mist the top of the loaf with water from the spray bottle and tap sweet rice flour over it, using a mesh tea ball or small sieve for an even layer.
If you like, score a wheat stalk design into each section between the parchment strips. It is a design only, so do not score across the top of the loaf. If you skipped the cuts around the base, snip the base of the dough along the long sides of the pan with kitchen scissors.
Tuck any parchment sticking up inside the pan and set the second loaf pan upside down on top as a lid.
Bake with the lid on for 30 minutes. Remove the lid and bake for another 15 minutes, until deeply golden.
Cool in the pan for 5 to 10 minutes, then lift out the loaf and remove the strings while it is still warm.
Push the cinnamon stick into the center of the top as the stem. Cool completely, 3 to 4 hours, before slicing.