Step 1: Prepare the Dough

1. Activate the yeast:
   In a small bowl, combine the warm milk and sugar. Sprinkle the yeast over the milk and stir gently. Let it sit for about 5 minutes until it becomes frothy. This step activates the yeast and gets it ready to help the dough rise.
2. Make the dough:
   In a large bowl, combine the yeast mixture, melted butter, salt, and egg. Stir everything together. Gradually add the flour, one cup at a time, mixing until the dough comes together. Don’t worry if it feels sticky at first—that’s exactly what you want.
3. Knead the dough:
   Transfer the dough to a lightly floured surface and knead for about 5-7 minutes until it becomes smooth and elastic. You can also do this in a stand mixer with a dough hook if you prefer. The dough should be slightly tacky but not overly sticky. If it’s too sticky, add a little more flour.
4. Let the dough rise:
   Place the dough in a greased bowl and cover it with a clean kitchen towel. Let it rise in a warm place for about 1 hour, or until it doubles in size.

Step 2: Make the Blueberry Filling

1. Cook the blueberries:
   In a saucepan, combine the blueberries, sugar, cornstarch, lemon juice, and cinnamon. Heat over medium heat, stirring frequently, until the mixture thickens and the blueberries start to break down, about 5-7 minutes.
2. Cool the filling:
   Once thickened, remove the blueberry filling from the heat and let it cool while the dough rises. This will help prevent it from becoming too runny when you spread it onto the dough.

Step 3: Roll Out the Dough

1. Prepare the dough for rolling:
   Once the dough has risen, punch it down to release the air. Turn the dough out onto a lightly floured surface and roll it into a large rectangle, about 12×18 inches. Try to get the dough as even as possible for nice, uniform rolls.
2. Spread the filling:
   Spoon the cooled blueberry filling evenly over the dough, leaving about an inch around the edges. You can use a spatula to spread it out.

Step 4: Roll and Slice the Dough

1. Roll it up:
   Starting from one of the longer sides, carefully roll the dough up into a tight log. Be gentle to avoid spilling the filling out. Pinch the seam to seal the roll.
2. Slice the dough:
   Use a sharp knife or dental floss to slice the dough into 12 even rolls. If you’re using floss, just slide it under the dough, bring the ends up, and pull tightly to make a clean cut. This keeps the rolls nice and neat.

Step 5: Bake the Rolls

1. Preheat the oven:
   Preheat your oven to 350°F (175°C).
2. Arrange the rolls:
   Place the rolls into a greased 9×13-inch baking dish, leaving a little space between each one. They will expand as they bake, so don’t worry if they seem snug at first.
3. Let them rise again:
   Cover the rolls with a kitchen towel and let them rise for another 30 minutes while your oven heats up. They’ll get nice and puffy.
4. Bake:
   Once the rolls have risen, bake them in the preheated oven for 25-30 minutes, or until they’re golden brown on top and cooked through.

Step 6: Make the Cream Cheese Frosting

1. Mix the frosting:
   While the rolls are baking, prepare the cream cheese frosting. In a medium bowl, beat the softened cream cheese and butter together until smooth. Add the powdered sugar, vanilla extract, and a pinch of salt. Beat again until everything is well combined and creamy.

Step 7: Frost and Serve

1. Frost the rolls:
   Once the rolls are done baking, let them cool for about 10 minutes. Then, generously spread the cream cheese frosting over the warm rolls. The frosting will melt into the rolls, creating a gooey, delicious topping.
2. Serve and enjoy:
   Serve these rolls warm, and watch them disappear! Pair them with a hot cup of coffee or tea, and enjoy the cozy vibes.