To prepare the pan

Remove the ribs of leaves for lining the pan (ti, banana, or lotus leaves). Quickly dip in hot water to soften.

Prepare a large baking pan by lightly oiling it. Line with heavy-duty foil then a thick layer (6-7 layers) of ti, banana, or lotus leaves. (In a pinch, a thick layer made up of several damp dish towels can be substituted for the leaves.)

Add one more layer of heavy-duty foil and oil generously. Set pan aside.

To prepare the batter

Boil wong tong (or brown sugar) and granulated sugar in water to dissolve the sugars. Cool.

Press the yams through a ricer.

Measure the Mochiko into a large bowl or pot. Add cooled sugar water and strained yams. Knead by hand until smooth. Batter should be the consistency of a thick pancake batter. If more liquid is needed to gain the desired consistency, use the reserved liquid from the canned yams.

Pour batter into the prepared pan. Completely cover the pan with heavy foil.

Bake at 350 degrees for 1½ hours. Turn down oven to 300 degrees and bake for another 1½ hours. Remove from oven and let cool. It’s best to cut with a plastic knife.