Instructions
1 Line an 18cm square cake pan with baking paper, extending paper 3cm over the long sides.
2 Place the bananas in a food processor and process until smooth. Stir in strawberries. Spread mixture into prepared pan, smoothing top. Freeze for 3 hours, or until firm.
3 Meanwhile, beat butter, oil, sugar and vanilla in a small bowl with electric mixer until pale and creamy. Add egg, beating well. Fold flour and cocoa powder into egg mixture. Turn dough out onto a floured surface. Knead until just smooth. Cover with plastic wrap, refrigerate for 1 hour.
4 Preheat oven to 180°C. Line 2 baking trays with baking paper. Roll the dough between 2 sheets of baking paper until 4mm thick. Cut dough into 20 x 6cm rounds. Transfer to prepared tray. Dock cookies with a fork in decorative pattern.
5 Bake for 10 minutes, or until light golden and crisp. Stand for 5 minutes before transferring to a wire rack to cool. Remove ‘ice cream’ from pan. Working quickly, using cookie cutter, cut into 10 x 6cm rounds. Sandwich ice cream slices between 2 biscuits.
6 See tips for how to melt the white chocolate. Using a sandwich or piping bag, pipe white chocolate around the sandwich. Sprinkle with dried strawberries. Place sandwiches in the freezer until chocolate is set.