Preheat your oven to 180°C (350°F). Line a 9-inch round cake pan with parchment paper and lightly butter the sides for easy removal.
In a large bowl, whisk the eggs and sugar together using an electric mixer on medium-high speed until thick, pale, and the mixture ribbons when dripped from the beaters, about 5 minutes.
Sift the flour and baking powder together, then gently fold them into the egg mixture in three additions, using a spatula to keep the batter light and airy.
Pour the batter into the prepared pan, smoothing the top with a spatula. Bake for 25-30 minutes, until the edges are golden and a toothpick inserted in the center comes out clean.
Remove the cake from the oven and let it cool in the pan for 10 minutes, then transfer to a cooling rack and cool completely for about an hour.
While the cake cools, hull and slice the strawberries. Toss them with a tablespoon of lemon juice and a teaspoon of sugar, then let sit for 15 minutes to macerate and become juicy.
In a chilled bowl, whip the heavy cream with sugar and vanilla extract until soft peaks form, about 3-4 minutes. Keep an eye on it to avoid over-whipping.
Using a serrated knife, carefully slice the cooled sponge horizontally into two even layers.
Place the bottom sponge layer on your serving plate. Spread a generous layer of whipped cream over it, then scatter a good handful of macerated strawberries on top.
Gently place the second sponge layer on top. Cover the entire cake with the remaining whipped cream, smoothing the sides and top with a spatula.
Decorate with extra strawberries or a light dusting of powdered sugar if desired. Cover loosely and refrigerate for at least 2 hours to let the flavors meld and the layers set.
Serve slices with a few fresh strawberries and a dollop of whipped cream for a delightful summer dessert.
