Place the ground beef in a large non-stick skillet over medium-high heat. Break it up with a spoon or spatula and cook, stirring occasionally, until browned and no pink remains — about 8–10 minutes. Add the bay leaves while cooking.

Remove the skillet from the heat. Carefully drain the excess fat and liquid through a fine-mesh strainer or tilt the pan and spoon it off. Return the skillet to medium heat.

Add the hoisin sauce and BBQ sauce. Mix well until the beef is evenly coated. Remove from heat. Discard the bay leaves. Set the filling aside to cool while you prepare the dough.

In a small bowl, mix the yeast and 1 tablespoon of sugar in 1 cup (240ml) of warm water — 100–110°F / 38–43°C — and let stand for 5 minutes until foamy.

Using a large mixing bowl, combine the flour, baking powder, and 1/4 cup sugar. Mix well, add 3 tablespoons of vegetable oil or shortening, then add the water-yeast mixture from earlier. Mix well with a large spoon or spatula until you form a dough. You can mix manually or use a hand mixer or stand mixer.

Knead the dough on a lightly floured surface for about 5 minutes or until it turns smooth enough. Shape the dough into a smooth ball and coat it lightly with the 1 teaspoon of vegetable oil reserved for this purpose. Place in a large bowl and cover with a clean kitchen towel or plastic wrap and leave for 1 hour in a warm area of your kitchen to rise until it doubles in size. While you wait, cut 10 small squares of parchment paper to lay the sealed siopao on when you steam them later.

Return to your lightly floured surface. Punch the dough to release the air and roll it into a log. Divide the log into 10 equal portions and shape each into a ball. For larger buns, divide into 8 equal portions. Weigh the portions on a kitchen scale for more uniform size, or eyeball it.

Using a rolling pin, take a ball and flatten it into a 5-inch (13cm) circle. Place about 2 tablespoons (30g) of filling in the centre of each circle. Gather the edges from one side towards the middle, pleating as you go until you reach the opposite end. Pinch the gathered edges firmly together, then twist to seal. Place each bun sealed-side down on a small square of parchment paper. Repeat with the remaining dough balls. Let stand for 10–15 minutes.

Lay the sealed siopao in a steamer about an inch apart, each on its parchment paper square. Steam for 15–20 minutes. The buns are done when the dough is puffed, matte white, and springs back when lightly pressed. Remove from the steamer and let cool for 3–5 minutes before serving.