Preheat your oven to 350°F (175°C) and prepare a round cake pan by greasing it with butter and lining the bottom with parchment paper.

In a heatproof mixing bowl, whisk together eggs and granulated sugar over a pot of simmering water until warm, then transfer to an electric mixer. Beat on high speed until pale and thick, about 6-8 minutes. Sift in cake flour while gently folding.

Pour the batter into your prepared cake pan and bake for approximately 30 minutes, or until the top is golden and springs back when pressed.

Remove the cake from the oven and let it cool in the pan for about 10 minutes before transferring to a wire rack to cool completely.

In a large mixing bowl, beat heavy whipping cream and powdered sugar on medium-high speed until soft peaks form, about 3-5 minutes.

Slice the cooled sponge into two or three layers. Place the first layer on a serving plate, spread whipped cream, and top with sliced strawberries. Repeat layering.

Cover the assembled cake loosely with plastic wrap and refrigerate for at least 3 hours before serving.