Butter the pan really well, then line it with parchment paper. Then butter the parchment paper. Set aside.
Sift the flour, baking powder and salt into a bowl. Set aside.
In a large mixing bowl, beat the eggs and sugar together. Start on low and gradually increase the speed to high and beat for about 5-8 minutes, until the mixture is thick and yellowish (see the pictures in the post for details).
Then add the oil and the vanilla and mix for 1-2 minutes more.
Gradually fold in the flour mixture, a little at a time, until it’s well combined. Don’t overwork it, though, otherwise you'll deflate the air that’s been incorporated.
Pour the batter into the baking tray and spread it out evenly covering the corners and edges.
Bake for 6-8 minutes until it's a little golden or until a toothpick inserted in the middle comes out clean.
Spread out a clean kitchen towel on your work surface and generously dust it with the powdered sugar (½ cup).
As soon as the cake comes out of the oven, immediately line it upright against the towel and let it drop on top of it.
Carefully remove the baking pan and the parchment paper.
Place the short end of the cake right in front of you. Then gently start rolling the cake together with the towel, but not too tightly.
Let the cake cool, as it is with the towel rolled up, for 1 - 1 ½ hours.
Make the filling
Wash and cut the strawberries into tiny pieces. Place them on a paper towel to absorb excess moisture so the cake won’t get soggy. Set aside.
Before beating the heavy cream, put a metal bowl in the freezer for about 10 minutes to help it whip faster.
Using a stand mixer or a hand-held mixer, beat the heavy cream with the powdered sugar and the vanilla until stiff peaks form, about 5 minutes. Put it in the refrigerator while the cake is cooling.
Unrolling, filling and re-rolling the cake
When the cake has completely cooled, gently unroll it and spread the whipped cream over the surface. Make sure you leave about ¼ of an inch border on all sides without filling. This will prevent any filling from oozing out.
Add the diced strawberries on top and gently press them into the whipped cream.
Starting at the far end, lift the towel and use it to gently roll the the cake towards you. Continue until it’s rolled completely.
Cover the cake with plastic wrap or the kitchen towel you previously used and put it in the refrigerator for 1-1.5 hours to firm up. I like to place it on a cutting board to make it easier to transfer.
When the cake is ready, you can cut off the ends for a cleaner look, if you prefer.
Right before serving, dust with powdered sugar and top with fresh strawberries.
Enjoy!
Store in the refrigerator for up to about 2 days.
Notes
Picture Tutorial & Tips: I have a detailed picture tutorial in my post to help you out with each step of the recipe as well as lots of tips to ensure success.
Carefully spread the batter out into an even layer in the tray, making sure it goes to all corners.
Don’t overbake the cake! It’s supposed to be a pale yellow color. If you overbake it, there’s a greater chance it will crack when you roll it because it becomes drier.
Flip the sponge cake onto a towel dusted with powdered sugar AS SOON AS IT COMES OUT OF THE OVEN.
DO NOT ROLL IT TOO TIGHTLY! You have to be very, very gentle with this cake, otherwise it will crack.
Once it’s rolled, let it COMPLETELY cool to room temperature.
After adding the filling and re-rolling the cake, it needs to set for at least 1 hour in the fridge before serving. This will also help to get nice, firmer slices, too.
Dust the baked cake with powdered sugar right before serving so it won't absorb into the cake.