Take a small skillet and heat over medium heat. Add in ¼ cup of whole black sesame seeds, and toast for 2 minutes, tossing and mixing occasionally to lightly toast the black sesame seeds and bring out the flavor. Transfer to a bowl and let it cool.

In a large mixing bowl, sift together 1 ¼ cup all-purpose flour, 1 tsp baking powder, and ¼ tsp of table salt. Whisk this together to mix.

In the bowl of your stand mixer, add in 4 tbsp of softened unsalted butter and ½ cup white granulated sugar. Mix on medium speed till they are combined and fluffy, about 1 minute. Scrape down the bowl as needed.

Add in 1 egg, ¼ cup of black sesame paste, 2 tsp vanilla extract, and ½ tsp orange zest. Mix these ingredients on medium-low speed just until combined. Scrape down the bowl as needed.

Turn the speed to low, and carefully add in the dry ingredients, and continue mixing until just combined. Detach the bowl from the stand mixer, scrape down the bowl as needed, and fold in any unmixed dry ingredients from the sides until the mixture is uniform. Add in the ¼ cup of toasted black sesame seeds and mix them in by hand till the dough is uniform.

Cover with plastic wrap, and rest in the fridge overnight (you can leave this dough in the fridge up to 3 days).

When your dough has been chilled overnight, preheat your oven to 350 F (175 C). Line a big sheet pan.

Measure out 3 tbsp of granulated sugar into one small bowl and ½ cup of powdered sugar into another small bowl.

Using a round tablespoon measure for scooping, scoop the chilled dough so you have a heaping tablespoon, about 1.5 tbsp worth of dough. Form them into spheres approximately 1 inch in diameter.

Roll the formed dough sphere first in the bowl of granulated sugar, then in the bowl of powdered sugar, and place them on the prepared baking sheet, about 2 inches apart.

Bake these in the preheated oven at 350 F (175 C) for 12 to 15 minutes. Let the cookies cool on the sheet pan for 5 minutes, then transfer them to a wire rack to cool completely.