1.Preheat oven to 180ºC. Grease a 19cm x 30cm lamington pan; line base and long sides with baking paper, extending paper 5cm over sides.
2.Beat eggs in a large bowl with an electric mixer for 10 minutes or until thick and creamy; gradually add sugar, beating until dissolved between additions. Fold in triple-sifted flours. Spread mixture into pan.
3.Bake about 30 minutes. Turn cake onto a baking paper-covered wire rack to cool.
4.Meanwhile, make jelly according to packet instructions; refrigerate about 2 hours or until jelly is set to the consistency of unbeaten egg white.
5.Trim and discard edges from cake; cut cake into 20 squares. Dip each square into jelly; toss in combined coconuts. Place on a tray, refrigerate 30 minutes.
6.Meanwhile, beat cream in a small bowl with an electric mixer until firm peaks form. Cut cakes in half; sandwich with cream.