Use a heavy saucepan and add the sugar to the pan.
Shake the pan so that the sugar distributes over the bottom.
Heat the pan until the sugar is dissolved.
The sugar will then changes color from light brown to amber brown. The temperature then becomes between 160 and 177 degrees Celsius. You can measure that with a special sugar thermometer. Turn off the heat and pour your caramel in the baking pan. (watch out for spatter because the caramel is very hot).
Allow to cool and harden.
Put the caramel in a plastic bag and beat with a rolling pin into small pieces.
Put your chocolate form ready on a baking sheet.
Break the chocolate into small pieces and melt au-bain-marie (heating the chocolate in a bowl hanging over boiling water) until all the chocolate is melted.
Put the bowl on your counter and pour 2/3 of the mixture on a cold surface, preferably a marble plate, and flatten it with a pallet knife, so that it cools and becomes thicker.
Wipe together, slide out again and add the cooled chocolate to the bowl with warm chocolate and mix well. Feel if the chocolate is lukewarm, about 37 degrees. Then the chocolate is tempered and ready to use.
Pour the chocolate into the molds, tap the side to force any air bubbles out and smooth the top.
Divide, according to your taste, the salt and caramel crumbs over the chocolates.
Let the chocolates harden for at least four hours in a cool place.