1. In a medium saucepan, whisk together the milk, heavy cream, sugar, cocoa powder, cornstarch, salt, and espresso powder until smooth.
2. Place the saucepan over medium heat, stirring constantly until the mixture begins to thicken and comes to a gentle simmer, about 8-10 minutes.
3. Once thickened, remove the saucepan from the heat and add the chopped dark chocolate and vanilla extract. Stir until the chocolate is completely melted and the pudding is smooth.
4. Pour the pudding into individual cups or ramekins and cover each with plastic wrap to prevent a skin from forming.
5. Refrigerate for at least 2 hours or until set. Enjoy chilled, perhaps with a dollop of whipped cream or a sprinkle of cocoa powder for an extra touch of elegance.

One of my fondest memories is helping my abuela stir her pots, learning the art of patience and timing. Remember to stir continuously to avoid lumps, and don’t rush the simmering process. The reward is a beautifully smooth and decadent pudding that’s worth the wait.