To Make the Filling
Grind the sesame seeds in a grinder or blender for about 20 secs. Then transfer ground sesame to a bowl and mix in ½ cup of brown sugar and a pinch of salt.
To Make the Dough
Prepare 3 cups of rice powder and sift into a large bowl.
Equally divide the rice powder into 3 bowls. Each bowl should now contain 1 cup of rice powder.
To prepare the basic white dough, add 3 tbsp boiling hot water to the rice powder and mix it with a spatula. When the dough is cool enough to handle, knead for about 5 mins, then wrap with cling film and set aside.
To prepare the green dough, add 1 tsp of ssukgaru (mugwort powder) and 3½ tbsp boiling hot water to the rice powder and mix it with a spatula. When the dough is cool enough to handle, knead for about 5 mins, then wrap with cling film and set aside.
To prepare the pink dough, add a pinch of strawberry Jell-o powder and 3 tbsp boiling hot water to the rice powder and mix it with a spatula. When the dough is cool enough to handle, knead for about 5 mins, then wrap with cling film and set aside.
To Assemble the Songpyeon
Cut off a piece of the dough and roll tightly between your palms in order to make a ball.
Press in to the ball with your thumb to stretch the dough slightly outwards and then use both of your thumbs to expand the opening.
Fill the well with ½ tsp of sesame filling, then seal tightly by squeezing the edges together. When the rice cake is sealed, shape them in to a half moon shape and set aside. Repeat until all the dough has been used.
To Cook
Prepare a steamer by bringing water to boil over high heat. Using pine needles or a damp kitchen cloth, line the bottom of the steamer to stop the rice cakes from sticking to the steamer.
When the water begins to boil, place the rice cakes on to the steamer ensuring that the pieces do not touch each other. Cover the rice cakes with a final, thin layer of pine needles if using.
Cover the steamer and let steam for about 20 mins.
Prepare a bowl of cold water and transfer the rice cakes in to the bowl when they’ve been cooked. Rinse the dumplings and then transfer to a rack to drain.
Lightly coat your hands with the sesame oil and use them to rub the oil on to the rice cakes.
To Serve
Serve immediately and while warm! Enjoy!