Sift 2 cups cake flour and 2/3 cup confectioners' sugar into a mixing bowl.

Cut in 1/4 cup butter until mixture resembles coarse crumbs.

Stir in 1/2 cup water until dough is formed.

Cover and refrigerate for 20 minutes to create the butter dough.

Sift 2 cups cake flour with 2 tablespoons confectioners' sugar in a small bowl.

Knead in 1/2 cup shortening until dough is formed.

Cover and refrigerate for 20 minutes to create the shortening dough.

Boil candied waxgourd in 1/2 cup water until nearly tender.

Drain the waxgourd.

Blend waxgourd to a paste.

Sift sweet rice flour and superfine sugar together in a bowl.

Mix in the sesame seeds.

Stir in 1/4 cup shortening and waxgourd paste.

Gradually stir in 2/3 cup of water, mixing until dough forms, creating the filling.

Preheat oven to 400 degrees F (200 degrees C).

Line 2 baking sheets with parchment paper.

Divide each dough mixture (butter and shortening doughs) into 25 equal portions.

Take one portion of the butter dough and roll out in the shape of a circle.

Wrap one portion of the shortening dough with the butter dough in the shape of a ball.

Roll the combined ball into an oval shape.

Roll the dough up lengthwise into a tube shape then roll out once more into a long strip.

Roll the dough up lengthwise again, pressing the ends down to secure.

Shape the dough into a circle.

Place the sweet rice flour dough into the center.

Wrap the outer dough around the filling creating a ball.

Flatten the pastry into a circle.

Place seam side down on the prepared baking sheet.

Repeat with the remaining portions.

Prick holes on the top of each pastry using a fork.

Brush each pastry with egg yolk.

Bake in the preheated oven until golden brown, about 20 minutes.

Cool in the pans for 10 minutes before removing to cool completely on a wire rack.