Hazelnut praline cream
1.Preheat oven to 180°C/350°F. Grease two deep 22cm (9-inch) round cake pans.
2.Beat eggs and brown sugar in small bowl with electric mixer about 10 minutes or until thick and creamy; transfer to large bowl.
3.Sift cornflour, cream of tartar and soda twice onto paper then sift over egg mixture; gently fold dry ingredients into egg mixture. Divide mixture into pans.
4.Bake sponges about 18 minutes. Turn immediately onto baking-paper-covered wire racks to cool.
5.Meanwhile, make praline. Stir sugar, the water and vinegar in small saucepan over low heat, without boiling, until sugar dissolves; bring to the boil. Reduce heat; simmer, uncovered, without stirring, about 10 minutes or until syrup is golden brown. Add hazelnuts; pour praline mixture onto baking-paper-covered tray. Cool about 15 minutes or until set. Break praline into pieces then blend or process until mixture is as fine (or coarse) as desired.
6.Beat cream in small bowl with electric mixer until firm peaks form; fold in praline.
7.Place one sponge on serving plate; spread with half of the cream mixture. Top with remaining sponge; spread with remaining cream mixture.
Sponge is best eaten the day it is made. Unfilled sponge is suitable to freeze for up to 1 month.Note