• Let’s break it down, step by step, for clarity.

Step 1: Prepare the Dough

• In a large mixing bowl, combine the yeast, sugar, and warm milk. Allow it to sit for about 5-10 minutes, or until it becomes frothy. This indicates the yeast is active and ready to go.

Step 2: Create the Dough Mix

• Add the softened butter, flour, cinnamon, and sea salt into the milk mixture. Stir until combined. Knead the dough on a floured surface until smooth. It should take about 5 minutes.

Step 3: Chill the Dough

• Shape the dough into a ball and place it in a greased bowl. Cover it with a damp cloth and let it rise in a warm area for about 60-90 minutes, or until doubled in size.

Step 4: Prepare the Butter Layer

• In a separate bowl, mix the flour and brown sugar with the softened butter. This butter layer is crucial for creating those delicious, flaky layers.

Step 5: Roll Out the Dough

• Once the dough has risen, roll it out onto a floured surface into a large rectangle. Place the butter mixture in the center, folding the dough over it.

Step 6: Laminate the Dough

• Roll out the dough again into a rectangle, then fold it into thirds like a letter. Repeat this process two more times, refrigerating the dough for about 30 minutes between each fold. This step is key for creating the flaky layers.

Step 7: Shape the Croissants

• Roll out the dough one last time. Cut it into triangles and place a chunk of chocolate at the wide end. Roll the dough towards the tip, making a crescent shape.

Step 8: Allow to Rise Again

• Place the shaped croissants on a baking tray lined with parchment paper. Cover them and let them rise for about 45 minutes.

Step 9: Brush and Bake

• Preheat your oven to 375°F (190°C). Mix the egg and milk to create an egg wash, brushing it over the croissants. Bake for 15-20 minutes, or until golden brown.

Step 10: Dust and Serve

• Once baked, allow them to cool slightly. A dusting of powdered sugar can optional but highly recommended for that beautiful presentation.