White chocolate collar
1.To make passionfruit curd, combine ingredients in a medium heatproof bowl over a medium saucepan of simmering water, stirring constantly, until mixture thickens slightly and coats the back of a spoon. Remove from heat. Cover surface with plastic wrap; refrigerate curd until cold.
2.To make white chocolate collar, combine the choc melts and oil in a heatproof bowl, stir over a saucepan of simmering water until melted. Cut three strips of baking paper, 10cm x 45cm, 9cm x 45cm, 8cm x 45cm, spread chocolate over paper strips on bench to completely cover strips carefully lift strips onto a clean bench; stand until almost set. Mark crossways into 4cm-wide strips, stand until firm. Re-cut or snap carefully into pieces. Set aside.
3.Preheat the oven to 200°C (180°C fan-forced). Grease two deep 19cm square cake pans; lightly flour the pans with a little plain flour and shake out the excess.
4.Beat eggs and sugar in a small bowl with an electric mixer until thick and creamy, about 7 minutes. For the initial beating, use a small bowl for maximum volume. To test if mixture is ready, turn off the mixer, lift beaters and the mixture should form thick ribbons. Transfer the mixture to a large bowl.
5.Sift the dry ingredients together twice onto baking paper. Sift the flour mixture a third time evenly over the surface of the egg mixture. Using a balloon whisk or large metal spoon, quickly and lightly fold the flour mixture through the egg mixture until just incorporated.
6.Divide mixture evenly between the pans; tilt the pans to spread mixture to the edge. Bake sponges for about 20 minutes or until the sponges spring back when touched lightly in the centre. Turn onto wire racks immediately, cool right way up.
7.Split sponges in half; sandwich both sponges with the passionfruit curd.
8.Beat cream and extract in a small bowl with an electric mixer until firm peaks form. Place one sponge on a serving plate, spread with a third of the whipped cream, top with remaining sponge.
9.To make passionfruit icing, sift icing sugar into a medium heatproof bowl, stir in the passionfruit pulp and water. Stir the icing, over a saucepan of simmering water until spreadable.
10.Quickly spread the passionfruit icing over the top of the cake. Spread the sides of the cake with remaining cream; press the chocolate strips around the edge of ribbon to secure. Top cake with flowers, if desired.
Not suitable to freeze. Chocolate suitable to microwave. Passionfruit curd is best made a day ahead. Recipe best assembled several hours ahead.Note