Step 1: Prepare the Dough (Night Before Baking)

Start by setting up your stand mixer with the dough hook attachment. In the mixing bowl, combine the whole milk, bread flour, sugar, instant yeast, salt, egg, and egg yolk. Mix on low speed until the ingredients start coming together into a shaggy dough. Increase the speed to medium and knead for 5-8 minutes until the dough looks smoother but still a bit sticky.

Next, gradually add in the room-temperature butter, one tablespoon at a time, making sure each addition is fully incorporated before adding the next. Continue kneading for another 5-10 minutes until the dough becomes soft, smooth, and elastic. It should pull away from the sides of the bowl but still be tacky to the touch.

Shape the dough into a ball, place it back into the mixing bowl, cover it with plastic wrap, and let it rise at room temperature for one hour. The dough won’t fully double in size at this stage, but it will puff up slightly. After the initial rise, transfer the dough to the refrigerator and let it proof overnight. This slow, cold fermentation enhances the flavor and makes the dough easier to handle the next day.

Step 2: Make the Blueberry Filling (Morning of Baking)

In a small saucepan over medium heat, combine the frozen blueberries, sugar, lemon juice, lemon zest, and cinnamon. Stir occasionally and let the mixture cook for 5-10 minutes, allowing the blueberries to release their juices and break down.

Once the blueberries have softened and released a good amount of liquid, transfer the mixture to a blender or use an immersion blender to puree it until smooth. Pour the puree back into the saucepan and return it to medium heat. Add the cornstarch slurry (cornstarch mixed with water) and cook for another 5-8 minutes, stirring constantly until the mixture thickens. Remove from heat and let it cool completely. It will continue to thicken as it cools, making it easier to spread on the dough later.

Step 3: Roll and Fill the Dough

Take the dough out of the fridge and let it sit at room temperature for about 10 minutes to soften slightly. Lightly flour your work surface and roll the dough into a 20” x 18” rectangle. Spread the cooled blueberry filling evenly over the dough, making sure to leave a small border around the edges.

Starting from the shorter end, carefully roll the dough into a tight log. Use a sharp knife or unflavored dental floss to cut the log into six equal sections. Place each section into a lightly greased jumbo muffin pan, cut side up. Cover loosely with a clean kitchen towel and let them rise for 30 minutes to 1 hour, or until they look puffy and slightly expanded.

Step 4: Bake the Muffins

Preheat your oven to 350°F (175°C). Once the muffins have finished rising, place them in the preheated oven and bake for 25-30 minutes, or until golden brown and firm to the touch.

Allow the muffins to cool slightly before adding icing. You can use a simple powdered sugar glaze, a classic cream cheese frosting, or even drizzle them with honey for a natural sweetness.