Begin by preheating your oven to 350°F (180°C) and lining the bottom of a 9-inch round cake pan or springform pan with parchment paper.

In a medium bowl, whisk together the flour, baking powder, and kosher salt, then set it aside.

In the bowl of a stand mixer fitted with the whisk attachment, add the room-temperature egg whites and lemon juice (or white vinegar). Beat on medium speed until the mixture becomes foamy.

With the mixer still running, slowly add half of the granulated sugar (½ cup or 100g). Increase to medium-high speed and continue whisking until stiff, glossy peaks form. The meringue should hold its shape on the whisk.

Using a rubber spatula, gently transfer the meringue into a separate bowl and set aside.

Next, add the egg yolks and the remaining ½ cup (100g) of sugar to the mixer bowl and beat on medium speed until the mixture becomes pale, thick, and doubled in volume, forming ribbons when the whisk is lifted.

While mixing, slowly drizzle in the oil. Scrape down the bowl, then gradually pour in the warm water and vanilla extract or paste. Mix for another minute to combine.

Sift one-third of the dry ingredients over the yolk mixture using a fine mesh sieve. Gently fold it in with a spatula, followed by one-third of the meringue. Repeat this process until all the flour and meringue are incorporated. Be sure to reach the bottom of the bowl while folding to avoid any unmixed flour, and do not overmix.

Pour the finished batter into the prepared pan. Bake for 25 to 30 minutes, or until the cake is golden and a toothpick inserted into the center comes out clean. Let the cake cool on a wire rack for 5 minutes before running a knife or offset spatula around the edges to release the cake from the pan. Allow to cool completely.

As the cake cools, make the syrup by combining the water, sugar, and sliced strawberries in a saucepan over medium heat. Stir until the sugar is completely dissolved and the syrup is hot. Remove from heat, transfer to a bowl or jar, and let cool. This syrup can be prepared a day ahead and stored in the refrigerator.

Strawberry Puree (Optional)

In a small saucepan, cook the strawberries and sugar over medium-low heat for about 5 to 7 minutes, or until the berries are soft and release their juices.

In a separate small bowl, whisk together the cornstarch and water, then stir this into the strawberry mixture. Increase heat to medium-high and cook just until it starts to bubble.

Remove from heat, then use an immersion blender or transfer to a blender or food processor to puree until smooth. Allow the puree to cool completely. This step can also be done a day ahead and refrigerated.

Before making the whipped cream, place your stand mixer bowl and whisk attachment in the freezer or fridge for 15 minutes to chill, which helps achieve better volume.

Once chilled, beat together the softened cream cheese, powdered sugar, and vanilla on low speed until smooth and creamy.

With the mixer on medium-low, slowly drizzle in the cold heavy whipping cream. After one minute, increase the speed to high and beat until stiff peaks form. Keep the frosting chilled until ready to use.

Once the sponge cake is fully cooled, use a serrated knife to carefully cut it into three horizontal layers. Place the bottom layer on a cake stand or serving platter and slide pieces of parchment paper under the edges to keep the surface clean.

Using a pastry brush or spoon, generously coat the surface of the bottom cake layer with the cooled strawberry simple syrup.

Spread a layer of whipped cream evenly over the top, making sure it reaches the edges. Arrange half of the sliced strawberries evenly over the whipped cream. Then add another layer of whipped cream on top of the strawberries, spreading it to cover completely.

Place the second cake layer over the filling and gently press down to eliminate any air pockets. Repeat the process with the syrup, whipped cream, remaining sliced strawberries, and another layer of whipped cream.

Before placing the top layer, brush the underside (the crumb side) with the syrup. Set this final layer crumb-side down and press gently.

Cover the top and sides of the cake with the remaining whipped cream, smoothing it out or styling it as desired. If you're using the strawberry puree for decoration, use a spatula to add small swipes of it across the top and sides of the cake, then smooth or swirl it into the frosting for a marbled effect or artistic finish.