• Preheat the oven to 350 F (180 C) for conventional oven. Please lower the temperature by 20 F (15 C) if using convection oven. Position the oven rack, 3rd from the top and another one 3rd from the bottom
• Prepare 2-3 large baking sheets lined with parchment paper

Prepare cookie dough:

• Place all the ingredients for cookie dough in a mixing bowl and combine into a soft dough. The dough shouldn't stick to your hands
  
• Portion the dough out into about 13-14 gram each (about 1 tablespoon). Roll it into round. You will get about 24 pieces of dough
• Place the dough on the prepared baking sheets, about 3 inches apart. Flatten the dough balls until they are about 2 inches in diameter. The cookies will spread.
  
• Sprinkle some white sesame seed on top of the flattened dough
  

Bake the cookies:

• Place the baking sheets on the positioned racks and bake for 7 minutes and then rotate the pans top to bottom and front to back and then continue baking for another 8-9 minutes. The cookies should be firm to touch
  
• I recommend baking only 2 trays at a time. Wait until the baking sheets have cooled down in between baking before using them again for the next batches

Cool down:

• Let the cookies cool down on the rack for 5 minutes and then transfer to a cooling rack to let them cool down completely

Prepare the filling: (only prepare when you are ready to assemble the cookies)

• Place black sesame paste, butter, and pinch of salt. Let it cook until the butter melts. Remove rom the heat. Then stir in powdered sugar and stir until combined
  

Assembling:

• Place 12 cookies upside down on your work surface.
  
• Place roughly about a tablespoon of filling in the center of each cookie.
  
• Top with another cookie on top of the filling to form a sandwich. Allow the filling to set for about 1 hour before serving the cookies