Preheat your oven to 170°C (340°F) and line an 8-inch round cake pan with parchment paper.

In a large mixing bowl, combine the eggs, sugar, and vanilla. Whip until pale and thick, about 5 minutes.

Sift cake flour over the egg mixture and gently fold it in. Do not overmix.

Incorporate vegetable oil and whole milk into the batter using a cut-and-fold method.

Pour the batter into prepared cake pan and bake for approximately 40 minutes. Check with a skewer.

Allow the cake to cool upside down on a wire rack until completely cool.

Blend your favorite fresh berries until smooth, strain, and combine with sugar and lemon juice in a saucepan. Cook for 10-15 minutes until thickened.

In a chilled bowl, whip heavy cream, mascarpone, and powdered sugar until fluffy with soft peaks.

Slice the cooled sponge in half horizontally. Spread berry coulis and pipe Chantilly cream on each layer, adding fresh berries in between.

Chill the assembled cake for 30 minutes. Apply a thin crumb coat of Chantilly cream and chill again for 15 minutes.

Decorate the top with fresh berries and dust with powdered sugar. Serve chilled.