Line a brownie/slice tray measuring 28cm x 18cm with baking paper and set aside.
Place Rice Bubbles in a medium mixing bowl.
Melt Mars Bars, butter and golden syrup in a medium-sized saucepan over a low heat. Stir until mixture is completely melted and smooth (Note: it may take a little while for the nougat in the Mars Bars to completely melt. Once it’s mostly melted, I remove the mixture from the stove and stir vigorously and this will blend all three ingredients perfectly). Do be careful that the temperature isn’t too high.
Pour chocolate mixture over Rice Bubbles and mix until well combined.
Press the Rice Bubble mixture into the prepared brownie/slice tray evenly using the back of a large metal spoon.
Put slice in the fridge until firm, approximately 15 minutes.
Break up the chocolate and place in a microwave safe bowl. Microwave in short bursts, stirring with a dry, metal spoon until chocolate is melted and smooth. Alternatively the chocolate can be melted on the stove in a double boiler.
Pour chocolate over slice and spread smoothly and evenly. Refrigerate for approximately 1 hour until set.
Remove slice from the fridge and cut into small squares. When cutting the slice, to get a really smooth, clean cut, run a sharp, serrated edge knife under hot water, dry and then slice. Repeat as often as needed until entire slice has been cut up. Serve and enjoy!
Recipe by Mrs Organised at http://www.mrsorganised.com.au/2015/10/02/mars-bar-slice/