1. To organize the filling, rub five-spice powder evenly over pork. Heat a grill pan over medium-high temperature. Coat the pan with cooking spray. Add pork to pan prepare 18 minutes or until a thermometer registers 155°, turning pork from time to time. Remove pork from pan, and let stand fifteen minutes.
2. Cut pork crosswise into thin slices cut slices into thin strips. Place pork inside a medium bowl. Add onions and then 7 ingredients (through 1/4 teaspoon salt) stir well to mix. Cover and refrigerate.
3. To organize dough, combine 1 cup tepid to warm water, sugar, and yeast inside a large bowl let stand a few minutes.
4. Gently spoon flour into dry calculating cups level having a knife. Add flour, oil, and 1/4 teaspoon salt to yeast mixture stir until a gentle dough forms. Turn dough out onto a gently floured surface. Knead until smooth and elastic (about ten minutes). Place dough inside a large bowl coated with cooking spray, embracing coat top. Cover and let increase in a hot place (85°), free of drafts, one hour or until bending in dimensions. (Lightly press two fingers into dough. If indentation remains, dough has risen enough.)
5. Punch dough lower let rest a few minutes. Turn dough out onto a clear surface knead in baking powder. Let dough rest a few minutes.
6. Divide dough into 10 equal portions, developing each right into a ball. Dealing with one dough ball at any given time (cover remaining dough balls to help keep from drying), roll ball right into a 5-inch circle. Place 1/4 cup filling out center of dough circle. Mention sides to pay for filling and meet on the top. Pinch and seal closed having a twist. Repeat procedure with remaining dough balls and filling.
7. Arrange 5 buns seam side lower, 1 " apart, in every tier of the 2-tiered bamboo steamer. Stack tiers cover with lid.
8. Add water to some large skillet to some depth of just one inch provide a boil over medium-high temperature. Place steamer in pan steam fifteen minutes or until puffed and hang. Awesome ten minutes before serving.