You’ll Never Guess the Surprising Ingredients in These Chocolate Truffles

Across many Asian countries, the Mid-Autumn Festival is among the most important holidays of the year, with families gathering together to celebrate the harvest moon. The festival’s emblematic treat is a sweet round pastry, commonly filled with the iconic combination of lotus seed paste and salted duck-egg yolks. The cakes are exchanged, admired for their designs, then enjoyed with loved ones, and Lieu’s Vietnamese family was no exception. “As a child, my favorite part of mooncakes were the egg yolks—some had double yolks,” she recalls. “I remember cutting them open, eating the yolk, and giving the remaining portion to my parents.”

But how to deliver the flavors, texture, and signature salted-egg-yolk center in an elegant, bite-sized gourmet truffle? Not surprisingly, the co-owner of San Francisco’s Socola Chocolates couldn’t locate anyone else who had achieved, or even tried, this transformation.

This wasn’t Lieu’s first time attempting a new twist on a nostalgic food—she had previously incorporated the essences of durian, Vietnamese coffee, and even Phở, all beloved flavors in her culture, into her chocolates. (Socola, after all, is the Vietnamese word for chocolate.) Still, mooncakes posed unique challenges. The hearty treats are baked, while chocolates are not, so one hurdle was achieving the proper consistency in a lotus seed paste, one of the most popular fillings among mooncake lovers. After some experimentation, the chocolatier discovered the ideal approach: soaking the lotus seeds, removing the tiny sprouts by hand, pressure-cooking them, mashing them into a paste, and—here’s the key—adding white chocolate into the filling.

Because Lieu envisioned customers delicately slicing her mooncake chocolates in half to reveal the tiny golden orbs within, the salted egg yolks had to hold their shape. She found that she needed to bury the yolks in salt and let them set for a month in the refrigerator before gently washing and baking them, then slicing them into diminutive balls. This lengthy process made sure they didn’t ooze into the filling.

In addition to the traditional filling, Lieu also created mooncake chocolates starring ube, black sesame, and jasmine tea, topped with colored splatters to match their defining ingredient. 

The mooncake chocolates are the cherry on top of what has been a full-circle entrepreneurial journey for Lieu, who launched Socola Chocolates with her sister Susan back when they were teenagers growing up in Santa Rosa, California. After school, the siblings would go to the nail salon their parents owned and visit the neighboring See’s Candies shop for free samples. Those See’s chocolates, which Lieu found to be overly sweet, inspired her to experiment with creating her own. She infused them with ingredients emblematic of her Vietnamese heritage—everything from sriracha and passionfruit to guava and cognac. When her customers tasted her chocolate truffles imbued with these classic flavors, the treats spurred long-forgotten memories. “It really opened up conversations about Saigon, back in the day,” she recalls.

The mooncake chocolates, Lieu says, are another homage to her culture. “I have so many memories of cracking open a tin, carefully cutting up each mooncake into individual bite-sized pieces, and sharing with family and friends.”