Combine the flour, yeast, salt, mashed sweet potato, water, cream, honey (or maple syrup), and egg in the bowl of a mixer (*Footnote 3). Mix with a pair of chopsticks or a fork until a shaggy dough comes together.

Attach the dough hook and knead on setting 4 for 5 minutes.

Add the softened butter to the mixer bowl. Continue kneading for another 5 to 10 minutes, until the dough is smooth and clinging to itself. If the dough is too wet and keeps sticking to the bowl after 3 to 4 minutes of kneading, slowly add more flour, 1 tablespoon at a time. And scrape off the dough from the wall of your mixing bowl. At the end of the kneading, the dough might be still sticking to the bottom of the mixing bowl and very soft, but you should be able to lift it with your hands.

Grease a bowl and your hands with butter or oil. Lift the dough from the mixer. Round the dough and tuck it under itself to create a smooth ball. Place it in the greased bowl. Cover with plastic wrap and let rise until doubled, 1 hour or so depending on your room temperature.

Once the dough has doubled in size, punch it down and flip it onto a well oiled working surface. Flatten the dough into a large square, about 10”x10” (25cm x 25cm). Cut into thirds in strips. Then cut each strip into four equal pieces to create 12 pieces of dough in total. You can also weigh the dough to create more evenly sized pieces - each dough ball should weigh 43 g.

Prepare a 11”x7” (28cm x 18cm) baking pan (*Footnote 4). Line it with parchment paper or grease the pan with butter or oil.

One piece at a time, pinch the edges of the dough into its center to create a tight ball. Then place it onto the working surface, seam side down. Cover the dough with your hand, shaped like a dome, so the dough touches your palm and fingers. Gently roll the bun in a circular motion to help seal the seam and further smooth the bun. Place the buns in the prepared baking pan.

After forming all the buns, cover the baking pan with plastic wrap. Let rise until the dough becomes 1.5 times the previous size, 30 to 45 minutes.

While the rolls are rising, preheat the oven to 350°F (176°C).

If not using canning syrup, combine the water and honey in a small bowl, stirring until the honey is fully dissolved.

Add half of the syrup to the remaining half an egg. Stir to mix well.

Once the rolls have fully risen, gently brush them with the egg syrup mixture. Sprinkle the toppings onto the buns if desired.

Bake at 350°F (176°C) for 20 to 25 minutes, until the tops of the buns turn a rich golden color.

When the buns come out of the oven, brush them with the remaining syrup.

Transfer into a ziplock bag once the buns are cooled completely, then store in the refrigerator for a week or in the freezer for up to 3 months. To reheat, microwave or warm the buns in the oven if refrigerated. Warm the frozen buns in the oven until thawed and warmed up throughout.