Melt chocolate and butter together, I cut the butter into smaller cubes to melt it easier. 30 seconds stir, then 15 more is what it took for me.
Crack the egg into the bowl of a mixer and whisk until foamy, about a minute. Then add in the sugar and salt gradually and whip until it is thick and a pale yellow, about 7 or so minutes.
Put the egg mixture into the chocolate, and then sprinkle the flour on top. Fold to combine until all incorporated.
Pour half the batter into each ramekin. Place them onto a cookie sheet and bake at 400°F for 10 minutes.
The middle should be barely jiggling, and they should have risen to the top of the ramekin.
Let cool for a couple minutes, then invert onto serving plates. Let them sit until the cakes release. DO NOT rush this process, that is why mine broke in a couple places. If you try to move them around before they are ready then the fudgy middle may come out all around the cakes.