The lava cake was invented by Chef Jean-Georges Vongerichten at his restaurant in New York. There is some dispute as to the original founder, but Chef Jean-Georges has been serving it on his menu for decades.
In a stand mixer with the whisk attachment on high-speed whisk together the eggs, sugar, salt, and vanilla extra until it turns white and is light and fluffy, which takes about 3-4 minutes.
At this stage, you can add them to buttered and floured ramekins and bake or spread out on a 13×9 casserole dish and place them in the refrigerator until completely cool.