In the United States, unsweetened chocolate is often called “bitter chocolate” (not bittersweet chocolate) or “baking chocolate.” In France, it’s called pâte de cacao, or cocoa paste, sometimes with a “99%” or “100%” notation before it. (Lindt makes a bar, which is available internationally. Otherwise check professional baking supply shops. In Paris, they stock it in bulk at
G. Detou.) If unsure, check the list of ingredients. Unsweetened chocolate will not have any sugar in the list of ingredients.
Cocoa nibs are available in well-stocked supermarkets, specialty food shops, and
online. If you can’t get them, or would prefer, you could use an equal amount of lightly toasted, chopped nuts, in place of them for the cocoa nib brittle. If you’ve not made caramel before, you may wish to review my post,
How to Make the Perfect Caramel, which includes step-by-step pictures.