2Tbspcrushed nuts of your choice(I used walnuts. Peanuts, almond slices and sunflower seeds are also popular choices.)
Sieve through the flour into a large bowl then add the salt, sugar, yeast and milk. Mix them well into a dough and cover the bowl with plastic wrap. Ferment it at a comfortable room temperature until the dough doubles in size. (Mine took 1 hour at room temperature 27 C/80.6 F but it could vary depending on the effectiveness of your yeast and also your room temperature.)
Once the dough is raised, release the gas by punching the dough with your hands a few times. Cover with the wrap again and rest for another 20 mins.
When the dough is ready, put some cooking oil on your hands (for anti stick purpose) and separate the dough to allow 6 medium sized pancakes to be made.
Put one of the pieces of dough on your hand, flatten the dough with your hands so that you can add about 1 Tbsp size filling onto it. Once it’s done, seal the dough by gathering the corners. Repeat this for the remaining dough.
Pre heat a frying pan on medium heat and once it’s heated add a thin layer of cooking oil.
Place a dough (1 or more depending on size of your pan. If more, allow enough room to expand between the dough when pressed down) into the pan and cook it on medium heat until the bottom side is lightly golden brown (about 30 seconds). Flip it over and press the dough down with a solid turner or professional hotteok press. Cook until the bottom part is golden brown (about 1 min). Flip the pancake over one last time then reduce the heat to low. Cover the pan with a lid and cook until the sugar filing fully melts (about 1 min). – It is still edible if you don’t further cook with a lid on but not all the sugar filling will be melted.
Transfer the pancake onto a plate and repeat step 6 for the remaining dough. Enjoy hot!