Instructions
1 Line an 18cm square cake pan with baking paper, extending the paper 3cm over long sides.
2 Place bananas and raspberries in food processor. Process until smooth. Spread the 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 flours into egg mixture. Turn dough out onto floured surface. Knead until smooth. Cover with plastic wrap, refrigerate 1 hour.
4 Preheat oven to 180°C. Line 2 baking trays with baking paper. Roll 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 into pattern.
5 Bake for 10 minutes. Stand for 5 minutes before transferring to a wire rack to cool completely. Remove ice cream from pan. Using cookie cutter, cut into 10 x 6cm rounds. Sandwich ice cream slices between 2 biscuits. Place sandwiches back in freezer.
6 To serve, dip one edge of each ice cream sandwich into the melted chocolate. Press the chopped pistachios into exposed edge of ice cream. Return to tray. Place in the freezer for 10 minutes. Serve.