Create caster sugar if needed by pulsing granulated sugar 15 times in a food processor. Set aside.
Line 8"x 12" or 9" x13" pan with parchment paper.
Preheat oven to 350°F.
Sift flour and salt together in medium bowl.
Separate egg yolks and egg whites into separate bowls.
Add caster sugar and vanilla to egg yolks. Whisk to combine. Set aside.
Whip egg whites on high until they have soft peaks using standing or handheld mixer and whisk attachment. Scrape into 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, and bang it against the counter twice.
Bake for 10 minutes. If not fully baked at 10, you can go up to 12.
Meanwhile, lay a piece of parchment on the counter and dust it with 2 Tbsp. of caster sugar.
When the cake is baked, carefully flip it immediately onto the parchment paper and remove the parchment paper it was baked on.
Score the short end closest to you 1/2" from the end. Fold the parchment closest to you over this end, 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 parchment.
When the cake is completely cool, add filling. Carefully unroll the cake and spread jam (or your desired filling) on the cake, leaving a 2" gap from one short end and a 1" gap on the long sides.
Spread the whipped cream on top. Top with strawberries.
Carefully re-roll the cake. Some filling may come out. Chill cake for 20 minutes in fridge. Slice 1/2" off each end to show off filling. Pipe additional cream on top if desired.