Chop the funsize Mars Bars into pieces and place into a microwaveable bowl with the reduced fat spread.
Microwave for 30 seconds, stir, and then microwave for another 30 seconds. Stir well - the mixture should be smooth.
Add the Coco Pops to the chocolate mixture and stir thoroughly, making sure that all of the Coco Pops are completely coated.
Spray a 20cm square baking tin with low calorie cooking spray and line the bottom with parchment paper. Press the mixture firmly into the tin.
Melt the white chocolate chips in the microwave, being careful not to overheat. Drizzle the white chocolate over the top of the crispy bites. Place the tin into the freezer for around an hour to firm up completely. You could also leave in the fridge overnight.