Combine the flour, sugar, instant yeast, and salt in a mixing bowl so the leavening is evenly distributed.

In a separate bowl, whisk warmed milk, melted butter, and the egg until combined, then pour the wet mixture into the dry ingredients.

Mix and knead—by hand or stand mixer with a dough hook—until the dough is smooth and slightly tacky, then cover and let it rise until doubled, about 1 hour in a warm spot.

On a floured surface, roll the risen dough into a rectangle roughly 12×9 inches.

Mix the blueberries with lemon juice and lemon zest; if berries are large, halve them so filling spreads evenly.

Spread the warm lemon-blueberry filling across the dough, leaving a 1/2-inch border, then roll the dough tightly from the long edge into a log and cut into even rolls.

Place the cut rolls in a greased baking dish with a little room between each so they can expand.

Cover loosely and let them rise again for about 30 minutes until puffy and nearly touching.

Preheat the oven to 350°F (175°C) and bake the rolls for 20–25 minutes until golden brown.

Watch the edges for deep browning; if the top browns too fast, tent loosely with foil.

While the rolls bake or cool slightly, beat room-temperature cream cheese with powdered sugar until smooth and spreadable.

You can thin the frosting with a splash of milk or lemon juice to make it drizzle-ready.

When the rolls are baked and cooled a bit, drizzle or spread the cream cheese frosting over them.

Serve warm for the best texture and fresh lemon aroma.