Preheat the oven to 140°C with fan or 150°C for conventional ovens. Line the base of an 8-inch cake pan with parchment paper. In a medium bowl, whisk together the egg yolks, milk, and oil until combined. Sift the flour and cornstarch into the egg yolk mixture and gently mix until smooth. In a separate bowl, using an electric mixer or a stand mixer fitted with a whisk attachment, whip the egg whites and sugar until stiff peaks form. Fold one-third of the meringue into the egg yolk mixture to lighten it, then carefully fold this mixture into the remaining meringue until just combined. Pour the batter into the prepared cake tin. Place the cake tin inside a water bath (a larger tray or tin filled with boiling water) and bake for 70 minutes. Once baked, remove the cake from the oven and let it cool completely. When cooled, run a knife around the edges of the cake pan and invert the cake onto a plate. Wrap the cake tightly in cling wrap and refrigerate until ready to assemble.

Using an electric mixer, whip the cream while gradually adding the sugar. Continue beating until stiff peaks form.

Combine the sugar and water in a small bowl and microwave for 30 seconds until the sugar dissolves; then let it cool. Slice half of the strawberries. Cut the cooled sponge cake horizontally into three even layers. Place one layer of cake on a serving plate and brush it with the simple syrup. Spread a layer of whipped cream over the cake, add a layer of sliced strawberries, then spread another layer of cream. Repeat the process with the next cake layer. Place the final sponge layer on top and apply a thin crumb coat of cream around the cake. Cover the entire cake evenly with the remaining cream. Fit a piping bag with a star tip, fill it with the leftover cream, and pipe a decorative border around the cake’s edge. Finish by decorating with the remaining whole strawberries.