1. In a small bowl, dissolve cane sugar in warm water. Mix gently and add yeast. Allow mixture to rest for 10 minutes.
2. In a larger bowl, knead together the flour and margarine until mixture resembles small beads. Add yeast mixture and mix gently with a spoon. On a floured cutting board, knead dough until it's smooth and pliable. Form into a ball and place back into a larger bowl. Cover with plastic wrap and allow to rise for about two hours.
3. In a medium skillet over medium-high heat, heat vegetable oil. Add seitan, salt, and pepper, and pan-fry for about 3 minutes on each side. In a medium bowl, mix hoisin sauce, chili sauce, and sour cream. Add fried seitan and set aside.
4. On a cutting board sprinkled with baking powder, divide dough into 12 flat rounds. In the center of each round, add a heaping tablespoon of the seitan mixture. Pull the sides of the rounds up to completely encase the seitan mixture and twist the dough to seal.
5. Fill a large saucepan 1/4 of the way with water, place over high heat, and bring to a boil. In a metal colander over the pot seam buns for about 15 minutes.