Activate the Yeast: In a large mixing bowl, combine the warmed milk, 1 tablespoon of caster sugar, and the active dry yeast. Stir gently and let it sit for 5-10 minutes. You'll know it's ready when the mixture looks foamy and bubbly on top, indicating the yeast is alive and well.

Prepare the Dough: To the activated yeast mixture, add the remaining 75g caster sugar, the whole egg, egg yolk, and the slightly cooled melted butter. Whisk until well combined. Gradually add the strong white bread flour and salt. Mix with a wooden spoon or a stand mixer with a dough hook until a shaggy dough forms.

Knead and First Prove: Turn the dough out onto a lightly floured surface (or continue in the stand mixer). Knead for 8-10 minutes until the dough becomes smooth, elastic, and no longer sticky to the touch. It should feel pliable and bounce back slightly when poked. Lightly grease a clean bowl, place the dough inside, turn it once to coat, then cover with cling film or a damp tea towel. Let it rise in a warm place for 1.5 to 2 hours, or until it has visibly doubled in size and feels light and airy.

Prepare Filling and Shape the Rolls: Once the dough has doubled, gently punch it down to release the air. Turn it out onto a lightly floured surface. Using a rolling pin, roll the dough into a large rectangle, roughly 40cm x 30cm (about 16x12 inches). It should be about 0.5 cm thick. Spread the softened butter evenly over the entire surface of the dough, right to the edges. Sprinkle the lemon zest evenly over the butter, followed by the fresh or frozen blueberries. Gently press the blueberries into the butter so they adhere.

Roll and Slice: Starting from one of the longer sides, carefully roll the dough into a tight log. Take your time to keep it as even as possible. Once rolled, use a sharp, un-serrated knife or a piece of dental floss to cut the log into 12 even slices, each about 3-4 cm thick. You’ll notice the beautiful spirals of dough, butter, lemon zest, and blueberries forming.

Second Prove and Bake: Lightly grease a 23cm (9-inch) round baking tin or a rectangular baking dish. Arrange the sliced rolls in the tin, leaving a little space between them as they will expand. Cover loosely with cling film or a damp tea towel and let them rise again in a warm place for another 45-60 minutes, or until they look puffy and have nearly doubled in size, touching each other. While the rolls are proving, preheat your oven to 180°C (160°C fan/Gas Mark 4). Bake the rolls for 25-30 minutes, or until they are golden brown on top, the kitchen smells gloriously of warm lemon and berries, and a skewer inserted into the centre comes out clean.

Make the Glaze and Serve: While the rolls are cooling slightly in the tin, whisk together the icing sugar and lemon juice in a small bowl until smooth. The glaze should be thick enough to cling to a spoon but thin enough to drizzle. Once the rolls are out of the oven and still warm, generously drizzle the lemon glaze over the top. The glaze will set slightly as the rolls cool. Serve warm, pulling apart the soft, sticky rolls.