Using a deep pan and a medium bowl (not plastic) warm up the water in the pan. Make sure the bowl is not contacting the water in the pan.
Melt dark chocolate in the bowl stirring from time to time.
When the chocolate is melted and no solid pieces remaining in the bowl spread it into 1/3 – ½ inch high rectangle on a baking sheet covered with baking paper and place in the fridge for 20 minutes.
Meanwhile the bottom layer is cooling down, melt the white chocolate in a clean bowl.
Repeat covering the cooled black chocolate layer with white chocolate. Top it with crushed candies and banana chips.
Place it into the fridge for 1 hour to fully cool down.