To make the dipping sauce, combine all ingredients in a small saucepan and place over medium heat. Cook, while stirring, until all the sugar is dissolved.
Remove from heat and let cool.
Sift the flour, baking powder, salt, and sugar into a medium sized mixing bowl. Slowly pour the boiling water into the flour mixture in a stream while mixing with a wooden spoon. Stir until a dough begins to form. If the dough is too dry, add more water, a tablespoon at a time until all of the flour is absorbed into the dough.
Turn the dough out onto a floured flat surface. Knead the dough until smooth, about 4 minutes.
Transfer to a greased bowl, cover; and let sit at room temperature for 90 minutes.
After 90 minutes, turn the dough out onto a floured surface and cut in half. Using a rolling pin, roll 1 half of the dough into a large rectangle (about 1/8” thick).
Brush the rolled dough with 1 Tbsp. of the sesame oil. Sprinkle with ½ cup of the thinly sliced green onion. If you like, sprinkle with red chili flake to taste.
Beginning with one long side of the rectangle, tightly roll the dough up. Cut the roll into 4 pieces. Lightly stretch each piece lengthwise, being careful not to rip dough. Beginning with one piece of dough, wrap it into a coil and tuck the end underneath. With your hand, gently flatten the dough. Using a rolling pin, roll the coil into a 4” circle. Repeat this process with the remaining dough pieces and with the remaining dough half.
You can layer the pancakes on a sheet tray with parchment paper in between as you complete them.
Heat 1 Tbsp. vegetable oil in a large non-stick skillet over medium-high heat. When pan and oil are hot, add one pancake to the skillet. Cook until golden brown on both sides, flipping only once (about 5-7 minutes). Repeat with remaining pancakes. If desired, keep the finished pancakes warm during production by laying them on a sheet tray in a warm oven.
To serve, cut pancakes into wedges. Serve with dipping sauce on the side.
Yields 8 4-inch pancakes. Recipe by Mandy Shook. Read the full blog here: http://bakers-blog.clabbergirl.com/scallion-pancakes-asian-take-classic-american-pancake/.