Line a 20 x 30cm slice pan with 2 layers of plastic wrap, extending 10cm over the sides. Arrange 2 rows of 6 wafers, side by side in the pan, leaving a 2cm gap down the middle of the pan.
Use an electric mixer to whisk the cream and condensed milk in a bowl until soft peaks form. With the beaters going, gradually add the coconut cream and whisk until just combined and the cream still holds its shape (be careful not to over-beat or beat too high as the mixture will curdle). Fold in the rice bubbles and frozen raspberries until just combined. Carefully spoon over the wafers and smooth the surface. Cover with rows of remaining wafers to line up with the base wafers, leaving a 2cm gap in the centre. Fold over the plastic wrap. Place in the freezer for 4 hours or until firm.
Use the plastic wrap to lift the ice cream slab out of the pan and onto a chopping board. Trim off the excess ice cream around the wafers and down the 2cm centre gap. Working from the centre, carefully slice the slab into 12 wafer-sized sandwiches. Place the sandwiches on a tray lined with baking paper and return to the freezer for at least 1 hour or until you are ready to decorate.
Take one ice cream sandwich from the freezer at a time, and dip one end into the melted chocolate to come 2cm up the sides. Sprinkle half the sandwiches with coconut and half with pistachio. Return each sandwich to the tray in the freezer. Repeat for remaining sandwiches. Place in the freezer for 1 hour or until firm.
