Blueberry Breakfast Buns

Dough

• 2 tsp dried instant yeast
• 2 medium eggs
• 110 g sugar
• 100 g whole milk
• 370 g strong white bread flour
• 50 g unsalted butter, soft
• 1 tsp vanilla extract
• 1 pinch fine sea salt

Filling

• 250 g fresh blueberries
• 70 g sugar
• 30 g plain flour
• 1 medium egg, lightly beaten, for brushing
• royal icing (可选的)