Activate the Yeast: Mix 1 cup sourdough starter, ¼ cup water, and 1 tablespoon active dry yeast in a small bowl. Let sit for 5-10 minutes until bubbly.

Combine Dry Ingredients: In a large bowl, whisk together 3 ⅓ cups flour, ¼ cup sugar, 1 teaspoon salt, and 1 tablespoon baking powder.

Mix Wet Ingredients: Add sourdough mixture, ¼ cup milk, ¼ cup melted butter, and 1 egg to dry ingredients. Stir until a shaggy dough forms.

Knead the Dough: Knead dough on a floured surface for 5-7 minutes until smooth and elastic.

Incorporate Blueberries: Gently fold in 1 cup blueberries, being careful not to over-mix.

First Rise: Place dough in a greased bowl, cover with a damp cloth, and let rise in warm place for 30-45 minutes until doubled.

Preheat the Oven: Preheat the oven to 350°F (175°C).

Shape the Rolls: Punch down dough, divide into portions, and shape into rolls. Place on a baking sheet lined with parchment paper.

Second Rise: Cover rolls with a damp cloth and let rise for 20-30 minutes.

Bake the Rolls: Bake for 25-30 minutes until golden brown.

Cool and Serve: Let rolls cool slightly on a wire rack before serving.