Sea salt chocolate gourmandize

This is MY MUM’s recipe!
My brothers and I have been living far from home for years now: my parents live in the center of France, Alexander studies in Britanny, Frederik works in Scotland and I am in Massachuetts. So every time we come back home, our mother, Mette, is requested to make our usual “Back-home cake”: her sea-salt chocolate cake. It is soft inside, crunchy outside, and we just cannot resist it!