Peel a carrot, cut into slices. Pour boiling water into the steamer pot, steam 160g carrot slices over medium high heat for 20 minutes.
Once carrots are tender, remove pot from heat and allow carrots to a cool a bit.
In a small bowl, dissolve 30g sugar in 35g warm water (*see note 2). Sprinkle 2.5g yeast over top of the liquid and allow the mixture to sit for ten minutes.
Transfer carrots to a blender. Do not add water at this step. The steamed carrots contain enough water. Puree carrots. I got 150g carrot puree for total. You can use 150g canned carrot puree if you want to skip the steaming step.
Add yeast sugar liquid into the carrot puree. Optionally add some red food color (see note 1). Blend at low speed for 10 seconds to mix well.
Put 250g all purpose flour in a large bowl, add the carrot puree to the flour, and stir using two chopsticks or a rubber spatula.
Knead with hands (or with a stand mixer) for about 5 minutes until all the ingredients are evenly mixed. It's okay if the dough doesn't look perfectly smooth at this moment. It will turn smoother after fermentation.
Shape the dough into a ball, cover it with a plastic wrap or a bowl to rest for 20 minutes.
While the orange dough is resting, make a white dough with similar steps: dissolve 10g sugar in 55g warm water, sprinkle 1g yeast over top of the liquid and allow the mixture to sit for ten minutes. Add the yeast mixture to 100g flour, knead the dough, shape into a ball, and let it rest.
While the white dough is resting, knead the orange dough with your hands or a stand mixer for 5 more minutes, until the surface is smooth. Cut and weigh out the orange dough (about 480g) into 2 portions (320g and 160g). Cut, weigh, and roll the 320g portion into 8 big balls (40g each). Then cut, weigh, and roll the 160g portion into 8 small balls (20g each). Set aside and cover with a plastic wrap.
Knead the white dough with your hands or a stand mixer for 5 more minutes, until the surface is smooth. Cut, weigh, and roll the white dough (about 160g) into 8 small balls (20g each). Set aside and cover with a plastic wrap.
Optionally, vertically cut across the center of a 40g orange ball for 3 times into 6 pieces. Shape the 6 pieces into a ball, so that it looks like an orange fruit. Repeat for the rest of the orange balls (40g ones).
Take a small ball (20g), use a rolling pin to roll it into a 3-inch-diameter circle wrap. Repeat until all 16 small balls (8 orange, 8 white) are rolled into 3-inch-diameter circle wraps.
Use a comb to print hundreds of holes on each orange wrap. Flip each orange wrap so that the smooth side is facing up.
Brush a thin layer of water on the smooth side of each orange wrap, place a white wrap on the top, gently press to stick them together.
Brush a thin layer of cooking oil on each white wrap, so that the "orange peel" can be peeled off easily after we steam the buns.
Place a 40g orange ball in the middle of the wrap. Use your thumb and index finger to pull up a corner of the wrap, fold, pleat, and go anticlockwise until you reach the end. Pinch to seal.
Cut a parchment paper into 4 inch squares. Place each bun on a square of parchment. Place the buns into the steamer, which you've just used to steam carrots. It provides a nice warm and humid place for buns to ferment. Place a toothpick in the middle of each bun. Keep the steamer's lid covered, let the buns ferment for 30 minutes.
30 minutes later, use the steamer to steam buns over medium heat for 20 minutes.
20 minutes later, open up the lid immediately to exposure the buns to cold air, so that the peels will shrink a bit, which makes our buns look more like real mandarin oranges.
Remove the toothpicks, and substitute with real orange steams and leaves.
Store your leftover buns in a food storage bag, and keep in the freezer. They will stay good for 6 months.