Place the room temperature eggs, sugar, vanilla and salt in a mixing bowl. Beat on medium high speed with whisk attachment until VERY light in color (pale yellow) and fluffy, about 10-15 minutes. Stop the mixer and let a dollop of batter fall into bowl, if it keeps its shape and doesn’t sink in then it’s done. However, if it quickly sinks back into the batter continue to mix and test again. **This step is what gives this cake its height. So be patient.