Line a 28cm x 18cm slice tin with baking paper.
In a medium saucepan, add butter and roughly chopped Mars Bars. Stir over a medium-low heat until melted and combined.
Place Kellogg's® Rice Bubbles® into a large heatproof bowl. Add Mars Bar mixture, stir until combined. Press mixture firmly into tin using the back of a spoon.
Place chocolate in a medium heatproof bowl. Place bowl over a medium saucepan of simmering water (don’t let water touch the base of the bowl); stir until chocolate is melted and smooth.
Spread evenly over the cooled slice. Refrigerate for approx. 2 hours or until set before cutting into small pieces.
