Here’s some Chef’s Tips, beyond this recipe:

I would use Droste Dutch Cocoa Powder (on Amazon). It is really good quality Cocoa Powder.

I would use either Vanilla Oat Malk or Chocolate Almond Malk instead of Milk.

And I would add some coffee to bump up the flavor of chocolate (as most good chocolatiers do). 

One more thing: If you are going decadent and buying online, I respect your wishes. I recommend Belgium Chocolates from CANDYGRAM®.