In a large bowl, stir together the flour, baking powder, baking soda and salt. Add the water and stir until the dough comes together; knead until the texture is, as Siu says, the same as your cheek. Cover the bowl with a towel and set aside for about half an hour.
Set a skillet over medium-high heat and melt the butter, oil and sesame oil.
Roll the dough out to a large oval as thin as you can get it. Dip a pastry brush into the melted butter-oil mixture and brush generously all over the dough. Sprinkle with chopped green onions and salt.
Starting at a long side, roll the dough cinnamon-roll style into a long roll. Cut crosswise into eight pieces. Squeeze and pinch the ends of each roll shut, twisting it slightly as you go. Flatten into a pancake with the twisted ends at the top and bottom.
Roll each out into a thin pancake between two pieces of parchment. (At this point, the cakes can be frozen, with layers of parchment in between—cook them straight from the freezer.) Cook the cakes in the hot skillet, with a bit more oil or butter if you need it, until they’re golden on each side. Serve warm, with hot sauce.