Prepare the Yeast: Measure ½ cup whole milk and pour it into a small bowl or mug. Sprinkle 1 teaspoon instant dry yeast evenly on top and let it sit for 2-3 minutes until the yeast becomes soft.
Prepare the Butter: Cut 2 tablespoons unsalted butter into small cubes and set aside.
Mix Dry Ingredients: In a stand mixer bowl, add 2 ½ cups all-purpose flour (and 2 ¼ teaspoons vital wheat flour if using), 3 tablespoons granulated sugar, and ¾ teaspoons kosher salt. Mix them with a spatula.
Combine Wet Ingredients: Add the beaten 1 large egg and the milk and yeast mixture to the bowl. Whisk the milk and yeast mixture before adding it to the bowl.
Initial Mixing: Turn the mixer on low and mix for about 1 minute, until the liquid is fully absorbed by the flour.
Knead the Dough: Increase the mixer speed to medium-high and knead for about 2-3 minutes until the dough tightens and forms a smooth ball.
Incorporate Butter: Reduce the mixer speed to low and add the butter. Knead for about 1 minute until all the butter is incorporated into the dough.
Final Knead: Increase the mixer speed to medium-high again and knead for another 3-4 minutes until the surface becomes smooth. Perform the windowpane test (note 4) to ensure you can stretch the dough into a thin membrane.
First Rise: Shape the dough into a ball and place it in a greased bowl. Cover with plastic wrap and let it rise for about 90-120 minutes, or until it has doubled in size (note 5). (Now is a great time to make the chocolate custard!)
Check the Dough: Dip your finger in flour and poke the dough. If the hole doesn't close, it's ready. If it does, let the dough rise for a few more minutes. Punch down the dough to remove gas, then transfer it to a lightly floured surface.
Divide the Dough: Divide the dough into 12 pieces (about 45g each) and shape them into small balls, making sure to seal the ends to prevent gas from escaping. Cover with plastic wrap or a kitchen towel and let them rest for about 5-10 minutes.
Prepare Cornet Molds: Grease the cornet molds with oil, but be careful not to over-oil them. I always spread oil with kitchen paper.
Shape the Dough (note 6 ):1. Flatten each ball and fold the top and bottom to the center, then fold in half and seal well.2. First, using your dominant hand, stretch the dough into a slight cone shape.3. Then, using both hands, roll it into a 35-40 cm cone shape, making the side on your dominant hand thinner and thicker towards the other hand.Note:- Make sure not to let any dough dry out while shaping. Cover the balls with a kitchen towel when working on the others.- If the dough keeps shrinking, cover it with a kitchen towel and let it rest. You can work on another piece of dough in the meantime, then come back and start shaping it again.- Avoid stretching the dough too much. The key to forming the dough is to keep the heels of your hands and fingertips anchored on the bread mat or pastry board. Let your palms gently arch to cradle the dough, and stretch it from the center outwards, as if you’re pressing out any trapped air. Wrap the Dough: Hold the cornet mold and start wrapping it around the thick end. Let gravity do the work—don’t pull the dough. For the first turn, roll it slightly over the top, then keep wrapping the dough to the top leaving a small gap between. Pull the end of the roll a little and tuck it under the dough. You should be able to make 6-7 levels. Place the thick end of the roll on a baking sheet lined with parchment paper, with the beginning of the roll facing down.Note: Make sure to wrap the dough around the mold right after you roll out the dough to prevent it from shrinking. Second Rise: Cover with a kitchen cloth to prevent drying and let rise for 15-20 minutes until the size increases by 1.5 times.Note: To prevent the dough from over-proofing, I like to work with 6 dough balls at a time. For example, shape 6 cornets and let them rise, then work on the next 6. Once the first batch is ready, bake it while the second batch finishes rising. Then, bake the second batch after the first one is done. Preheat the Oven: Start preheating the oven to 400°F (200°C) while letting the dough rise.
Egg Wash and Bake: Brush the surface of the cornets with beaten egg yolk and bake for about 9-10 minutes, or until the surface is golden brown.
Cool: Remove the bread from the molds while they’re hot and let them cool. To do this, hold the bread gently with one hand and twist the mold with the other (be sure to wear a glove).