Activate the yeast: In a small bowl, combine the warm milk (or water), yeast, and sugar. Let it sit for 5-10 minutes, or until it becomes frothy.

Make the dough: In a large mixing bowl, combine the yeast mixture, softened butter, salt, egg, and 2 cups of the flour. Mix until well combined. Gradually add the remaining flour, one cup at a time, mixing after each addition, until the dough becomes smooth and elastic.

Knead the dough: Turn the dough out onto a floured surface and knead for about 8-10 minutes until it becomes soft and elastic.

Let the dough rise: Place the dough in a greased bowl, cover with a damp cloth, and let it rise in a warm place for about 1 hour, or until it doubles in size.

Prepare the filling: In a small bowl, mix together the softened butter, brown sugar, and cinnamon.

Roll out the dough: Once the dough has risen, punch it down and turn it out onto a floured surface. Roll the dough into a 12×18-inch rectangle.

Add the filling: Spread the cinnamon-sugar butter mixture evenly over the dough, leaving a small border around the edges. Sprinkle the blueberries over the filling.

Shape the rolls: Carefully roll the dough up tightly from one long edge into a log. Slice the log into 12 rolls and place them into a greased 9×13-inch baking pan.

Second rise: Cover the rolls with a damp cloth and let them rise for another 30-45 minutes, or until they have puffed up.

Preheat the oven: While the rolls are rising, preheat your oven to 350°F (175°C).

Bake: Bake the rolls for 20-25 minutes, or until golden brown.

Prepare the glaze: While the rolls are baking, whisk together the confectioners’ sugar, milk, and vanilla extract until smooth. Adjust the consistency with more milk if needed.

Glaze the rolls: Once the rolls are baked and slightly cooled, drizzle the glaze over them before serving.