When the dough has proofed and has doubled in size, remove the plastic wrap and towel and punch the dough down. Then, split the dough into 2.
Wrap one part with plastic to keep moist and spread the other one out using a rolling pin.
Use a bowl to cut circles into dough.
Spoon 2 or so tablespoons of filling into each circle.
Seal the buns by flipping the sides over the filling and pinching them together.
Then lay buns down, with the sealed side on the bottom on a parchment-lined baking tray.
Repeat until all the dough and filling are used up.
Preheat oven to 175 degrees Fahrenheit, place a damp kitchen towel over the stuffed buns, and place them in the oven to proof for another 30 minutes.
When they are done, they should be slightly bigger.
Remove the proofed stuffed buns from the oven
And, preheat the oven to 375 degrees Fahrenheit.
Beat the remaining egg and brush it over the buns.
Sprinkle buns with sesame seeds and place in a 375-degree Fahrenheit oven for 20-22 minutes so buns bake and tops are golden.
When time is up, remove buns from the oven and turn the oven off.
Enjoy buns warm or at room temperature.