To make the ice-cream, combine the frozen bananas, avocado, maple, cocoa and salt in to a food processor and process until well-combined and smooth. Scrap down the sides as you go. 

Place the soft-serve in a freezer safe container to set for a few hours until firm or serve as a soft-serve.

Pre-heat your oven to 160 degrees C.

Cream together the sugar and butter in a large mixing bowl before adding the vanilla. 

Add the wholemeal flour and combine to a soft dough. Knead within the bowl and bring the dough together in to a ball. It may be a little sticky depending on your flour. 

Wrap the dough in cling film and place in the fridge for at least 30 minutes.

Remove the dough from the fridge and roll it out on a lightly floured surface. If the dough is sticky, knead in the additional flour. 

Roll out to around ½ centimetre before cutting rounds with a cookie cutter or glass. 

Line a baking tray with baking paper and lay the rounds out evenly. 

Bake in the oven for 12 - 15 minutes before removing and allowing to cool. The shortbreads will crisp up as they cool.

When cool, place a round down and, using an ice-cream scoop, place a ball of ice-cream on the round. Place another round on top and press down to make a "sandwich". Serve immediately or store back in freezer, covered for up to three days.