Spectacular dragon beard candy with thousands of silky sugar threads is an ancient art form. A family treat with delicate sweetness and nutty filling.
In a heavy-bottom saucepan over medium-high heat, combine corn syrup, granulated sugar, water, and white vinegar. Stir gently until the sugar dissolves, then stop stirring to prevent crystallization.
Attach a candy thermometer and continue heating until the syrup reaches 260°F (hard ball stage). Immediately remove from heat to avoid overcooking and pour the hot syrup into a lightly greased heatproof dish.
Allow the syrup to cool until it is just warm and pliable, about 15–20 minutes. Oil your hands lightly, then stretch and fold the mass repeatedly until it turns opaque and resembles a soft dough.
Roll the sugar dough into a thick loop. Dust with cornstarch to prevent sticking, then begin stretching the loop, doubling and twisting repeatedly. Work quickly and steadily to form thousands of thin, silky threads.
Finely chop the peanuts and combine with toasted sesame seeds. Pinch off a small portion of sugar threads, flatten in your palms, and place a spoonful of nutty filling inside. Fold the threads over to form bite-sized candies. Dust lightly with more cornstarch if needed to prevent sticking.