Korean sweet filled pancakes often sold as street food are called hotteok.
Hotteok is made from a yeasted wheat-flour dough that is filled, pressed flat, and fried on a greased griddle. Traditional fillings commonly combine brown sugar, honey, chopped peanuts or other nuts, and cinnamon. As the pancake cooks, the sugar melts into a hot syrup inside, making hotteok especially popular as a winter snack.
The food is generally believed to have entered Joseon Korea with Chinese merchants during the late 19th century, during the Qing dynasty period. Korean cooks and vendors adapted the filled dough snack to local tastes, particularly by favoring sweet fillings. Today, both traditional stalls and commercial dry mixes are common in South Korea.
Hotteok should not be confused with tteok, the broad Korean category of rice cakes, or bungeoppang, a fish-shaped pastry usually filled with red bean paste. Savory versions also exist, including yachae-hotteok, which can contain vegetables and japchae-style noodles.