Pork-Belly Buns

INGREDIENTS

• 2 1/2 lb skinless boneless pork belly, cut into quarters
• 1/2 cup reduced-sodium chicken broth
• 1/2 teaspoon active dry yeast
• 1/2 cup sugar
• 1 cup warm water (105-115°F), divided
• 1/2 cup kosher salt
• 4 1/2 cups water, divided
• 3 1/2 cups cake flour (not self-rising)
• Accompaniments: hoisin sauce; thinly sliced cucumber; chopped scallions
• 3 tablespoons sugar plus a pinch
• 2 tablespoons nonfat dried milk
• Canola oil for greasing and brushing
• 1 1/2 teaspoons baking powder