Spray 8″ x 12″ or 9″ x 13″ baking sheet pan with cooking oil and line with parchment paper.Preheat oven to 350°F.Sift flour and salt together in a medium bowl.Separate egg yolks and egg whites into separate bowls.Add sugar and vanilla to egg yolks. Whisk to combine. Set aside.Whip egg whites on high until they have soft peaks using a standing or handheld mixer and whisk attachment. Scrape into a clean bowl and clean mixer.Whip egg yolk mixture on high for approximately 5 minutes until the mixture has grown 3 to 4 times in size and batter has reached the ribbon stage. If you remove the whisk, you should be able to draw a figure 8 with the batter and have it hold for 4-5 seconds before it disappears.Fold in the flour mixture.Fold in the egg white mixture.Pour the batter into the prepared pan, even with an offset spatula.Bake for 10 minutes. If not fully baked at 10, you can go up to 12. Don’t over bake.Meanwhile, lay a clean cloth towel on the counter and dust it with 2 Tbsp. of powdered sugar.When the cake is baked, carefully flip it immediately onto the towel and remove the parchment paper. It should peel off easilyFold the cloth towel over end nearest you, and begin to slowly roll up the Swiss Roll cake until the whole cake is rolled.Let the Swiss Roll Cake cool completely rolled in the cloth.