In a rectangular heat-resistant pan, combine all ☆ ingredients, and mix. Cover with a lid at 90 degrees but keep it open a crack (or wrap in plastic wrap).
Microwave for a minute, remove, mix with a fork, then return it to the microwave. Be careful not to burn yourself. Repeat the process until it becomes transparent and reaches a jelly-like consistency.
Cool in a large pan filled with water. Once cool, close the lid and chill in the refrigerator for at least an hour.
The transparent mixture will turn cloudy. Any small bubbles that may have formed should also disappear.
Sprinkle kinako on top, cut in the center cross-wise with a spatula or knife, then agitate the pan to loosen the contents.
Cut the two sections into half again so that contents are sectioned into quarters. Sprinkling kinako along the cuts will free the edges and keep them from sticking.
Quarter the sections lengthwise to make 16 rectangular pieces.
Use a spatula to cut around the pan edge to free the cakes from the pan completely. Cover with a lid and shake vigorously. Sprinkle evenly with kinako, then it's ready to serve!
Transfer to serving dishes and drizzle with homemade brown sugar syrup. Bon appetit.
You can leave out the sugar if you wish.
Story Behind this Recipe
I was inspired by user "Manmonmari"'s recipe to make warabimochi using tapioca, but wanted to make it an easy recipe that is good for people suffering from inflammation. After I posted my first version, I revised it with a simpler recipe with an easy proportion of ingredients and doesn't waste any kinako.
If you want it to be more springy, reduce the amount of water to 3/4 cup (approx. 177 ml). If it appears to be too hard in Step 2, add more water. This recipe uses a US cup measure (approximately 250 ml), but you can also use the same proportions with a Japanese cup measure (which will yield a slightly smaller amount).