Mash the steamed sweet potato finely while warm for easier mashing.

Add room temperature butter to the mashed sweet potato and mix well.

Sift cake flour, corn starch, and baking powder into the mixture. Add black sesame seeds.

Mix roughly with a spatula, then knead the dough by hand until it comes together.

Place the dough in a plastic bag, roll it flat with a rolling pin, and refrigerate for 30 minutes.

Cut the chilled dough into stick shapes using a scraper or knife.

Shape the dough into sticks of appropriate thickness for a crispy texture after baking.