Sweet, salty, buttery caramel enrobed in dark chocolate and sprinkled with fleur de sel.
Pour into baking pan and cool in the fridge 2 hours. Cut into 1-inch pieces. Dip each piece in melted dark chocolate, then let harden on a wire rack.
*This stage can be determined by dropping a spoonful of hot caramel into a bowl of ice cold water. If it has reached soft-ball stage, the caramel easily forms a soft ball pinched between fingers while in the cold water but starts to melt after a few seconds. If the ball is firm, that's okay, too, but take it off the heat immediately.