Transfer the milk to a pot and warm it up on medium heat, mixing continuously.
Add the chocolate and let it melt.
Optional: Add the cinnamon or the black pepper.
Keep mixing. You should obtain a smooth thick mixture.
Pour it into cups and serve hot.
Notes
Expert Tips:
Use high-quality chocolate. The quality of chocolate you use will have a significant impact on the taste of your hot chocolate. Use a good quality dark or semi-sweet chocolate with at least 70% cocoa solids.
Add the chocolate to the milk mixture slowly. To prevent the chocolate from clumping or burning, add it to the milk mixture in small pieces and stir continuously until it has melted.
Adjust the sweetness to your taste. The amount of sugar you use will depend on your personal preference. Start with a small amount and add more as needed.