The key ingredients required to make Blueberry Buns include flour, sugar, salt, dry yeast, lukewarm milk, melted butter, an egg, fresh blueberries, additional sugar for the filling, and lemon juice and zest. The flour forms the base of the dough, contributing to its structure and texture. Sugar not only adds sweetness but also enhances browning during baking, giving the buns a lovely golden color. Salt is crucial as it balances flavors and strengthens the dough. The dry yeast is essential for leavening, allowing the buns to rise and become soft and fluffy. Lukewarm milk helps activate the yeast and enriches the dough, while melted butter adds moisture and a rich flavor. The egg serves as a binding agent and contributes to the dough’s tenderness. The blueberries, combined with extra sugar, lemon juice, and zest, create a vibrant, fruity filling that bursts with flavor, contrasting beautifully with the soft dough. Together, these ingredients work harmoniously to create an irresistible sweet treat.