Rice Cake Balls Coated with Black Sesame Seed Powder (Heukimja-gyeongdan)

Chewy confections made with glutinous rice flour, these rice cake balls are filled with red bean paste, then coated with toasted black sesame seed powder. I love the powder’s nutty taste and beautiful black color, but if you’d like to make some of your rice cake balls a striking contrasting color, pick up yellow castella (a bright-colored pound cake) from a Korean or Japanese bakery, make crumbs from it, and coat some of your rice cake balls with the crumbs.

Makes about 75 rice cake balls

INGREDIENTS:

• ½ cup azuki beans, picked over, rinsed, and drained
• 3 cups water
• ½ cup packed light brown sugar
• Kosher salt
• 3 cups glutinous rice flour (chapssal-garu)
• 3 cups boiling water
• 1 cup toasted black sesame seeds
• All-purpose flour for dusting

INSTRUCTIONS:

1. Put the beans in a medium heavy saucepan, add the 3 cups water, cover, and cook over medium-high heat for 30 minutes.
2. Turn the heat down to low and simmer until the beans are very soft and easy to mash, about 1½ hours longer. There should be just a little bit of liquid left in the pot. If the beans are still hard, add more water and continue cooking over low heat until soft.
3. Remove the pan from the heat and mash the beans with the remaining liquid, using a wooden spoon. (The consistency should be like that of canned refried beans.) Add the brown sugar and ½ teaspoon salt. Cook over medium-high heat, stirring with the wooden spoon, until the paste thickens and turns dark and shiny, about 5 minutes. Scrape the paste into a bowl.
4. Combine the rice flour and 1 teaspoon salt in a large bowl. Add the boiling water and mix with a wooden spoon until the dough is cool enough to handle. Then knead in the bowl until the dough is soft and smooth, about 5 minutes. Put the dough in a plastic bag and let sit on the kitchen counter for 30 minutes.
5. Grind the sesame seeds in a spice or coffee grinder until fine and powdery.
6. Dust a cutting board or a baking sheet with flour. Pull a little piece of dough out of the plastic bag and roll it between your hands into a ½-inch ball. Make a hole in the middle of the ball with your thumb to turn the ball into a cup. Put about ½ teaspoon bean paste into the middle of it, pinch together to seal, and roll again into a smooth ball. Place on the floured board. Repeat with the remaining dough and filling. You should have about 75 rice cake balls.
7. Bring a large pot of water to a boil over high heat. Add all the rice cake balls and stir with a wooden spoon to prevent them from sticking to the bottom of the pot and to each other. Boil until the balls float, 3 to 5 minutes. Drain the rice cake balls in a colander, transfer them to a large bowl, and cover with cold water to rinse and cool them. Drain again.
8. Put the sesame seed powder in a shallow bowl. Roll the cooked rice cake balls in the powder to coat. Transfer to a serving plate and serve, or freeze the rice cake balls in an airtight container for up to 1 month. Defrost on the countertop before serving