1 Preheat oven to 180 C. Grease and line three large oven trays.
2 Combine butter and chocolate in a heatproof bowl over a saucepan of simmering water (do not allow water to touch bowl). Stir until melted; set aside.
3 Beat eggs, sugar and vanilla in a small bowl with an electric mixer for 10 mins or until thick and creamy. Fold in sifted flour, then chocolate mixture; allow to stand 10 mins.
4 Spoon mixture into a large resealable plastic bag or disposable piping bag fitting with a 1-cm plain tube. Pipe 4-cm rounds, about 5 cm apart, onto prepared trays. Bake for 8 mins or until puffed and beginning to crack. Cool on trays.
1Combine chocolate and butter in a medium heatproof bowl; place bowl over a saucepan of simmering water. Stir until melted and smooth. Whisk in icing sugar; cool to room temperature. Beat with a wooden spoon until thick and spreadable.
2Match up cookies into pairs the most similar in shape and size (there will be slight variation).
3Pipe Chocolate Frosting onto half the cookies, then sandwich together with remaining cookies.
Bauer/The Australian Women's Weekly/ Photo: Alan Benson
Text: Evol Ferguson