Peel the skin from the sweet potato, soften by boiling or heating in the microwave, and mash.
Add margarine and sugar to a bowl and stir.
Add sweet potato from Step 2 and mix.
Mix in the sifted cake flour.
Divide into 2 equal portions and wrap. Mold into rectangular sticks, and chill in the fridge overnight.
Slice into 8 mm ~ 1 cm pieces.
Line up on a cookie sheet, and brush the surface with egg yolk.
Shake black sesame into the center of the cookies. Bake them in a 355°F/180°C oven for 15-20 minutes, until they turn a delicious golden brown.
They are done. They are really fragrant right after baking.
Story Behind this Recipe
I love the "Aunt Stella" limited edition fall sweet potato cookies. This is the result of trial and error adjusting the ingredients.It tastes a bit different, but I was able to make delicious sweet potato cookies.
If you can, I recommend "browned butter margarine." I think it is sold at any supermarket .