In a large mixing bowl, combine 1 cup of warm milk and 2 tablespoons of granulated sugar. Sprinkle in 2 teaspoons of active dry yeast, letting it bloom for about 5 minutes until foamy.

Add 4 tablespoons of melted unsalted butter and 1 large egg to the mixture. Whisk everything together until combined.

In a separate bowl, whisk together 4 cups of all-purpose flour and 1 teaspoon of salt. Gradually incorporate the dry mixture into the wet ingredients.

Knead the dough on a lightly floured surface for about 8-10 minutes until it is smooth and elastic. Place in a greased bowl, cover with a damp cloth, and let it rise for about 1 hour.

Punch the dough down gently and roll it out into a large rectangle. Spread 1 cup of blueberry jam evenly over the dough.

Roll the dough tightly from one end to the other and slice into 12 equal pieces. Place in a greased baking dish and let them rise for another 30 minutes.

Preheat your oven to 350°F (175°C). Bake for 25-30 minutes until golden brown.

While the rolls are baking, prepare the frosting by beating cream cheese with powdered sugar and blueberry puree until smooth.

Once the rolls are out of the oven, let them cool for about 10 minutes before frosting them generously.