Brilliant! That’s how I would call the intuition of Chris Taylor and Paul Arguin, authors of Fabulous Modern Cookies. They took the Asian technique of Tangzhong and applied it to cookies that use fresh fruit – like pumpkin, bananas, and in this case, sweet potato.
From the King Arthur Baking website, “The Tangzhong Technique is an Asian technique — which has origins in Japan’s yukone (or yudane) and was popularized across Asia by Taiwanese cookbook author Yvonne Chen — cooks a small percentage of the flour and liquid (water or milk) in a yeast recipe very briefly before combining the resulting thick slurry with the remaining ingredients.
How does this technique affect yeast dough? It pre-gelatinizes the starches in the flour, meaning they can absorb more water. In fact, flour will absorb twice as much hot water or milk as it does the cool/lukewarm water or milk you’d usually use in yeast dough.
Not only does the starch in the flour absorb more liquid; since heating the starch with water creates structure, it’s able to hold onto that extra liquid throughout the kneading, baking, and cooling processes. “
Taylor and Arguin took it even further. They realized that the Tangzhong technique could be used to absorb the excess liquid when using fruit that would provide too much moisture. Later on I will post a recipe for Banana Chocolate Chip crisp cookies form their book, using the same method.
The original recipe called for pumpkin, but I had just returned from our farm share pick up, and I had plenty of sweet potatoes, so I used a baked sweet potato instead. These cookies are delicious and so easy to bake, a mix between Snickerdoodles and Crinkles, with plenty of cinnamon flavor, the caramelized depth of dark brown sugar, and the confectioners’ sugar coating.