Preheat the oven to 170°C.
Sift the flour and baking powder into a large mixing bowl.
Add the eggs, butter, caster sugar, and vanilla to the bowl.
Whisk ingredients with an electric hand whisk for one minute until smooth.
Divide the mixture between two 20cm tins and level the surfaces.
Bake in the center of the oven for 30 to 35 minutes.
Ensure cakes spring back when touched before removing from the oven.
Cool for five minutes in the tins before moving to a wire rack.
Peel off the parchment paper and allow cakes to cool completely.
Scoop passion fruit flesh and seeds into a small bowl.
Whisk mascarpone, fromage frais, sugar, and vanilla together in a bowl.
Fold two-thirds of the passion fruit into the cream mixture.
Spread half the filling on the first cake layer.
Drizzle remaining passion fruit over the filling and top with more cream.
Place the second sponge on top and dust with sifted icing sugar.