In a large mixing bowl, use electric beaters to mix the eggs and sugar until light and fluffy. This should take about 5 minutes.
Gradually add in the flour and cocoa powder, mixing on low until just combined.
Pour in the melted butter, vanilla, and salt, and mix on low until just combined. Set the batter aside.
Prepare a water bath. Place a greased 8×8” pan inside a larger dish (like a 9×13” pan). Add warm water (almost boiling) to the larger dish until it reaches halfway up the sides of the 8×8” pan.
Bake on the lowest oven rack for about 1 hour and 15 minutes. The center should still be gooey, so don’t over-bake.
