I used to melt unsweetened chocolate, add butter or heavy cream (pretty much the same thing), and a small amount of erythritol. Makes for a nice snack. The added fat makes the result a bit softer, as well as tastier, but just how soft depends on how much fat. I only make enough to fit in an 8-oz. dish, which is four rectangles of Baker’s chocolate, plus other ingredients added by eye.
These days I don’t go to the trouble. I just eat a serving of the chocolate straight from the box. Funny how tasty it is, when a few years ago I thought it was so bitter as to be inedible!