In a microwave-safe bowl or small saucepan, gently warm the milk and butter together until just lukewarm, about 60–90 seconds. Stir until the butter is fully melted. The mixture should feel warm to the touch but not hot.

In the bowl of a stand mixer fitted with a dough hook (or paddle attachment to start), combine the flour, instant yeast, salt, granulated sugar, and lemon extract. Pour in the warm milk mixture and add the egg. Mix on low–medium speed for 2–3 minutes until a soft dough forms. (Optional: Add in a small bit of yellow food coloring to give them the lemon-yellow color!)

Transfer the dough to a lightly floured surface and knead for 10–15 minutes, until smooth and elastic. Place the dough into a lightly oiled bowl, turning once to coat. Cover with a kitchen towel or plastic wrap and let rise in a warm place for about 1 hour, or until doubled in size.

While the dough rises, make the filling. In a bowl, mix together the softened butter, granulated sugar, lemon juice, lemon zest, heavy cream, and lemon extract until smooth and spreadable. Set aside.

Once the dough has doubled in size, turn it out onto a lightly floured surface. Roll the dough into a large rectangle with an even thickness. Spread the filling evenly across the dough, leaving a small border around the edges. Sprinkle the blueberries evenly over the filling.

Starting from the long side, tightly roll the dough into a log.

Using dental floss or a sharp knife, cut the log into evenly sized rolls. Place them into a buttered baking dish, leaving a little space between each roll. Cover and let rise again for about 45–60 minutes, until puffy.

Preheat the oven to 350°F (175°C). Bake the rolls for 28-30 minutes, or until lightly golden and baked through. Remove from the oven and allow them to cool slightly.

In a bowl, whisk together the powdered sugar, heavy cream, and lemon extract until smooth. Adjust with a splash more cream if needed for a drizzleable consistency.

Drizzle the glaze over the warm rolls. Serve while warm for the softest, fluffiest texture.