Place the white chocolate in a medium-sized heat-proof bowl. Heat the heavy cream in the microwave until just below a boil (*Footnote 1). Pour it over the finely chopped white chocolate. Let stand for 1 minute, then whisk until smooth.

Whisk in miso until smooth. Cover with plastic wrap and refrigerate for 2 hours or so, stirring occasionally, until the texture firms up and can hold its shape, but still spreadable.

Add the white sesame seeds into a small pan and cook over medium heat. Stir frequently and turn to medium low heat when the pan is hot. Cook until the sesame seeds smell very fragrant and the color slightly darkens. Immediately transfer to a bowl to cool.

In a stand mixer mixing bowl, add the butter and powdered sugar. Mix with paddle attachment at medium speed until thoroughly combined and slightly lightened in color, 2 minutes or so. Add the completely cooled white sesame seeds and salt and mix again to combine.

Add the all-purpose flour on low speed in 2 additions, and mix again until just combined.

Place a sheet of parchment paper (half the size of a sheet pan) on a clean working surface. Place the dough in the center, and spread it out evenly with your hands. Place another piece of parchment on top. Roll with a rolling pin into a rectangular sheet that is about 1/4” (6 mm) thick. Transfer the dough (with parchment paper) onto a baking sheet and chill in the fridge until firm, about 1 hour.

Preheat the oven to 350ºF (176ºC).

When the cookie dough is firm, peel off the top parchment paper and then place it back onto the cookie dough. Flip the cookie dough and place it onto a working surface. Peel off the other piece of parchment. Using a cookie cutter, cut out rounds and place them on a parchment-lined baking sheet. Once you cut all the dough, you can gather the remaining dough, roll it out, chill it, and cut out more cookies.

Bake at 350ºF (176ºC) for 12 to 15 minutes until the edges turn light golden.

Transfer the baking sheet to a cooling rack to cool completely.

To assemble the cookies, transfer the miso cream into a piping bag with 1/4” round tip. Pipe in about 2 teaspoons of filling onto the center of the bottom of a cookie. Place another cookie onto it, bottom side onto the filling. Press gently until the filling spreads out to the edges.

Once all the cookies are assembled, store them in the fridge until completely cooled before serving, about 2 hours, up to overnight. (*Footnote 2)