01 - Combine warm milk and yeast in a large bowl. Let stand for 5 minutes until mixture becomes foamy and fragrant.
02 - Whisk sugar, melted butter, eggs, and salt into the yeast mixture. Gradually incorporate flour until a soft, sticky dough forms.
03 - Turn dough onto a lightly floured surface. Knead for 8–10 minutes until smooth and elastic. Transfer to a greased bowl, cover, and let rise in a warm area for 1 hour until doubled.
04 - Mix brown sugar and cinnamon in a small bowl. Toss blueberries with 1 tablespoon flour in a separate bowl to prevent bleeding.
05 - Punch down risen dough and roll into a 16x12 inch rectangle. Spread softened butter evenly, sprinkle with cinnamon-sugar mixture, and distribute floured blueberries.
06 - Roll dough tightly from the longer edge into a log. Slice into 12 equal pieces using a sharp knife or unflavored dental floss.
07 - Place rolls cut-side up in a greased 9x13 inch baking dish. Cover and let rise for 30–45 minutes until puffy and visibly expanded.
08 - Preheat oven to 350°F. Bake rolls for 22–25 minutes until golden brown on top and cooked through in the center.
09 - Whisk powdered sugar, milk, and vanilla extract until smooth and drizzling consistency. Pour over warm rolls immediately before serving.