Dissolve cane sugar in warm water in a small bowl, add yeast, and let it rest for 10 minutes until foamy.

In a large bowl, knead flour and margarine until the mixture resembles small beads.

Add the yeast mixture to the flour mixture and gently mix with a spoon.

Knead the dough on a floured cutting board until smooth and pliable.

Form the dough into a ball, place it back in the bowl, cover with plastic wrap, and let it rise for about 2 hours.

While the dough is rising, heat vegetable oil in a medium skillet over medium-high heat.

Add seitan, salt, and pepper to the skillet and pan-fry for about 3 minutes on each side until browned.

In a medium bowl, mix hoisin sauce, chili sauce, and vegan sour cream.

Add the fried seitan to the sauce mixture and set aside.

Sprinkle baking powder on a cutting board.

Divide the dough into 12 flat rounds.

Place a heaping tablespoon of the seitan mixture in the center of each round.

Pull the sides of the dough up to completely encase the seitan mixture and twist the dough to seal.

Fill a large saucepan 1/4 of the way with water and bring to a boil over high heat.

Place the buns in a metal colander over the pot and steam for about 15 minutes.