• Preheat oven to 350°F (or 180℃).

  Line and grease a 9 x 13 x 2 metal baking pan.

MAKE THE CRUST:

• In the bowl of your stand mixer, measure and add the unbleached  all-purpose flour, coconut, powdered sugar and kosher salt. Then mix until combined.
• Next add the softened butter and add it to the flour mixture. Mix on low until the dough forms wet crumbles.
• Transfer the coconut shortbread it into the prepared pan. And with your impeccably clean fingers, press it evenly on the bottom and up the sides (about ½-inch) of the pan.
• Partially bake the coconut shortbread crust on the middle rack of your preheated oven for approximately 18 to 20 minutes, or until lightly golden.
• Once baked, immediately reduce the oven temperature to 325°F (OR 160°C).

MAKE THE FILLING:

• While the crust is baking, make the filling. In a food processor, measure and add sugar and lemongrass paste (or scant 1/2 cup of chopped fresh lemongrass), and pour in the lemon juice. Blend until combined.
• Add eggs and blend for 10-15 seconds. Add the flour and a pinch of kosher salt; pulse a few times until incorporated.
• Once the crust has baked, immediately pour the lemongrass mixture onto the hot coconut crust and place in the oven for 20 minutes or until the filling has set.
• Cool in pan for 30 to 40 minutes. Then use the parchment paper to lift it out of the pan (if it sticks at all, use a sharp knife and run along the edge that is stuck) and transfer to a wire rack to finish cooling.

  Cut in to twelve squares, dust with powdered sugar and serve!