Brioche Dough

1. In a bowl, rehydrate the yeast with the warm milk and let rest for 10 minutes.
2. Place the flour, sugar, and salt in the bowl of a stand mixer fitted with the dough hook.
3. Add the milk-yeast mixture, egg, and softened butter, then knead on medium speed for 5–7 minutes until the dough is smooth and slightly sticky.
4. Cover with a kitchen towel and let rise in a warm place for 1 1/2 to 2 hours, until doubled in size.

Blueberry Filling

1. In a saucepan, combine the blueberries, sugar, lemon juice, water, cornstarch, and cinnamon.
2. Cook over medium heat for 5–7 minutes, stirring, until thickened.
3. Mash slightly if desired, then let cool completely.
4. Set aside about 2 tablespoons of the filling for the frosting.

Shaping & Baking

1. Preheat the oven to 350°F (180°C). Grease a large rectangular baking dish.
2. Transfer the dough to a lightly floured surface, gently deflate, and roll into a large rectangle about 5 mm thick.
3. Spread the cooled blueberry filling evenly over the dough.
4. Roll tightly into a log and cut into 2–3 cm slices using a sharp knife or dental floss.
5. Arrange the rolls in the baking dish, leaving space between them.
6. Cover and let rise again for 45 minutes to 1 hour.
7. Bake for 25–30 minutes, until lightly golden. Let cool slightly.

Blueberry Cream Cheese Frosting

1. In a bowl, whisk together the cream cheese, butter, powdered sugar, vanilla, and reserved blueberry filling until smooth.
2. Spread over warm rolls and serve.