Crispy deep-fried nian gao with a golden shell and gooey center is an indulgent festive treat. A family favorite during Chinese New Year celebrations.
Cut the nian gao into ½-inch thick slices for even frying and set aside.
In a mixing bowl, combine all-purpose flour, cornstarch, sugar, and salt. Whisk briefly to blend.
Add the egg and cold water to the dry mixture, whisking until a smooth, lump-free batter forms. The batter should be thick enough to coat the nian gao.
Heat the neutral oil in a deep heavy-bottomed pan over medium-high heat until the temperature reaches 350°F (use a kitchen thermometer for best results).
Dip each nian gao slice into the batter, ensuring a full even coat, then gently lower into the hot oil.
Fry batches of nian gao for 2–3 minutes per side, flipping once, until golden brown and crisp on all sides. Do not overcrowd the pan.
Transfer fried pieces onto a paper towel-lined plate to drain excess oil, and allow to cool slightly before enjoying for the ideal gooey texture.