Step 1

In a bowl, whisk together the flour and the baking soda. Set the bowl aside.

Step 2

Add the granulated sugar and orange zest into another bowl. Use your fingers to work the zest into the sugar, until you can no longer feel any large clumps of zest. The sugar should take on a light orange hue at this stage.

Step 3

Fit your stand mixer with the paddle attachment. Add the butter, sugar and zest mixture, brown sugar, and miso paste to the bowl of the stand mixer. Mix the butter and sugar mixture on medium-low speed until the dough is light and fluffy, about 2 to 3 minutes. The dough should stick to the sides of the bowl at this stage, so scrape down the sides with a silicone spatula. Add the egg, soy sauce, and vanilla, and mix on medium-low to incorporate, about 30 seconds.

Step 4

Add the flour to the bowl all at once and mix on low until just incorporated.

Step 5

Scoop out 1/3 of the pale yellow cookie dough and put it in a bowl or tupperware that you’ll use to chill all the cookie dough later. Set it aside. Scoop out another 1/3 of the cookie dough and set it aside (you’ll add this back into the mixing bowl very shortly).

Step 6

Dot 4 or 5 heaping tablespoons full of the black sesame paste on different parts of the dough in the mixing bowl.

Step 7

Return the portion of pale yellow cookie dough you just set aside by placing it on top of the dough with the sesame paste blobs. Then, dot the remaining sesame paste over the cookie dough.

Step 8

Mix the dough on low for 2 to 3 seconds (see note 3). Do not overmix. It is okay if the black sesame streaks are a little uneven.

Step 9

Carefully transfer this black sesame dough into the same bowl/tupperware as the unmixed dough. It's okay to place the two types of dough side-by-side (see photo below). Chill the dough for at least 3 hours or overnight.

Step 10

Preheat the oven to 350ºF (175ºC). Position an oven rack to the center position of the oven. Line 2 large half-sheet baking pans with foil (dull side up) or parchment paper. (See note 4 for more notes about baking on foil vs parchment paper.)

Step 11

Grab a large #16 ice cream scoop (see note 5). Scoop about a tablespoon of pale yellow cookie dough into the scoop. Next, scoop out some of the swirled black sesame dough (about 2 tablespoons). Continue alternating between the pale yellow dough and the swirled black sesame dough until you have filled up the scoop with cookie dough. (See note 6)

Step 12

Release the cookie dough from the scoop. I don't usually weigh the cookie dough, but for reference, each cookie should be about 80 to 85 grams. If there's too much pale yellow dough at the top, pinch some black sesame dough and spread it over the pale yellow portion. This will make the top look more marbled.

Step 13

Add 1/4 teaspoon of white sesame seeds into a small bowl. Roll the rounded top of the cookie dough in the bowl with the sesame seeds until the surface is covered in seeds. Transfer the cookie dough to a lined sheet pan. Continue shaping 3 more portions of cookie dough and topping each portion with 1/4 teaspoon of sesame seeds.

Step 14

These cookies spread quite a bit, so bake 4 cookies at a time on a half-sheet baking pan. You'll also bake these cookies one sheet at a time, so chill the remaining cookie dough as the first batch of cookies are in the oven.

Step 15

After shaping several cookies, I like to use a silicone spatula to scrape off the dough from the inside of the scoop.

Step 16

Bake the cookies for 8 minutes. Wearing oven mitts or using pot holders, grab onto the baking sheet and lift it several inches above the oven rack. Bang the cookie sheet onto the rack to bang the cookies. The cookies should deflate slightly and create a ripple around the edges. Rotate the baking sheet to ensure even baking. Bake the cookies for another 2 minutes. The cookies should have puffed up again. Wear oven mitts or use pot holders to bang the cookies again. Continue baking and banging the cookies at 2-minute intervals 2 more times, until you have baked the cookies for a total of 14 minutes. The edges of the cookies should be a golden brown color. If the edges are not brown enough, bake for another minute.

Step 17

Take the cookies out of the oven and let them cool for 15 minutes. The centers of the cookies are very soft at this point. The cookies need to cool on the sheet so the centers can set. If you baked the cookies on foil, slide a large flat spatula under the cookies to lift them off the sheet and transfer to a cooling rack. If you baked the cookies on parchment paper, they should come right off the parchment.

Step 18

As the first batch of cookies cools, prepare another batch of cookies and bake them using the cooking times specified above. Continue until you've baked all the remaining dough.

Step 19

These cookies taste best once they have cooled completely. Store the cookies in a container for up to 3 days.