In a small bowl, combine 1 2/3 cup all-purpose flour and 1 tsp baking powder and mix with a fork. (I so this extra step so that baking powder is evenly distributed when sifting).

With a fine mesh sieve, sift the flour mixture over a medium bowl.

Each log should be 10 inched (25 cm) long with 1 inch diameter.

Prepare a small flat container (or baking sheet) and add black sesame seeds (save the white one for later a time). Moist a sheet of paper towel with water and wrap around a log so the dough is moisted.

Roll the other 2 longs in the black sesame seeds and wrap in parchment paper or plastic.

Meanwhile, prepare oven to 180ºC. For a convection oven, reduce cooking temperature by 15ºC. Prepare a baking sheet lined with parchment paper.

Cut the rest of the cookie dough and transfer to the baking sheet lined with parchment paper. If the dough is no longer chilled, you can put the baking sheet in the refrigerator for 15 minutes until the cookies are chilled and firm. (If the cookie dough is chilled, they will not completely lose their shape).

Remove from the oven and allow to cool on the baking sheet for 5 minutes before transferring to a wire rack to cool completely.

Enjoy the cookies with cup of hot green tea.

Note:

These cookies stay fresh in an airtight container at room temperature for up to 1 week. I usually reheat the cookies (180ºC) in the toaster oven until toasty.

To freeze the dough:

Tightly wrap the logs in plastic wrap and put them into freezer bags. Freeze for up to 3 months. Let them thaw in the refrigerator for 2 hours before slicing.