Delicate mung bean cake with a smooth, crumbly texture is a refined Chinese pastry. A family recipe with fresh, naturally sweet bean flavor.
Rinse the dried mung beans, then soak them in cold water for at least 3 hours to soften fully; this ensures a smoother texture.
Drain mung beans and steam over medium-high heat for 40 minutes until very tender, taking care not to let the beans dry out.
Transfer steamed mung beans into a food processor and blend until completely smooth, scraping down the sides as needed.
While still warm, mix in unsalted butter, granulated sugar, vanilla extract, and salt; stir gently to incorporate, managing moisture to achieve a crumbly yet smooth consistency.
Pack the mixture tightly into small cake molds, then chill in the refrigerator for 1 hour to set before unmolding and serving.