Method

1. To make the Sponge Layers, place the oven rack in the lower third of the oven and then preheat it to 180°C (160°C fan-forced). Brush two 20cm shallow (sandwich) cake tins with a little melted butter to lightly grease. Line the bases with circles of baking paper. Lightly brush the paper with a little more melted butter and then dust the bases and sides of the tins with a little flour to lightly coat, tapping out any excess.
2. Use an electric mixer with a whisk attachment on medium-high speed to whisk the eggs in a medium bowl until frothy. Add the sugar a spoonful at a time, whisking well between each addition, until the mixture is very thick and pale and the sugar has dissolved (this will take about 8 minutes). Lift the whisk out of the mixture and draw a figure eight, if the trail stays on the surface long enough for you to finish drawing then the mixture is ready. If not, continue to whisk for a further minutes and then test again.
3. Meanwhile, heat the milk and butter in a small saucepan over medium heat until the butter melts and the mixture is almost simmering. Remove from the heat. Pour the hot milk mixture down the side of the bowl with the egg mixture. Quickly sift the flour and cornflour together over the egg mixture and then immediately whisk again with the electric mixer briefly, until the flour mixture is just incorporated (make sure there is no flour caught at the bottom of the bowl and be careful not to overmix).
4. Divide the mixture evenly between the cake tins (see Baker’s Tips) and gently tap the tins on the bench top three times to settle the mixture. Bake in preheated oven for 18-20 minutes or until the cakes are a pale golden colour, spring back when lightly touched in the centre and start pulling away from the sides of the tins. Remove from the oven and stand for 1 minute before turning onto a wire rack, top side up (see Baker’s Tips), to cool completely.
5. When ready to fill, to make the Passionfruit Icing, sift the icing sugar into a medium bowl. Add the passionfruit pulp and enough boiling water to mix to a thin, spreadable icing. Cover tightly with plastic wrap and set aside. Use an electric mixer with a whisk attachment or a balloon whisk to whisk the cream in a medium mixing bowl until soft peaks form. Use a large metal spoon or spatula to gently fold the passionfruit pulp through the whipped cream until just swirled through. Place one layer of the sponge on a serving plate or cake stand and spread with the passionfruit cream. Top with the remaining sponge layer. Spread the Passionfruit Icing evenly over the top layer of the sponge, allowing it to drip down the sides slightly. Set aside or 20 minutes or until the icing sets before serving in slices.