Prepare Baking Tin: Line a square 8x8 inch baking tin with parchment paper. Set aside.
Set Up Double Boiler: Set up a double boiler by placing a large heat-proof mixing bowl over a pot of simmering water.
Melt Ingredients: Add the butter, sweetened condensed milk, and broken-up dark chocolate into the bowl. Gently melt the ingredients over low heat, stirring until completely melted and smooth, then turn off the heat. TIP: Be careful not to overheat; if the mixture seems to separate after melting, it's still fine to use.
Combine with Coco Pops: Pour the Coco Pops into the melted chocolate mixture. Stir well to ensure it’s evenly coated.
Press into Tin: Transfer the mixture to the lined baking tin. Using a rubber spatula or your hands to press the mixture firmly into the tin to even out the top and ensure it's compact. This helps prevent crumbling when slicing.
Chill and Set: Refrigerate the slice for 1-2 hours, or until it has solidified.
Serve: Remove the slice from the fridge, lift it out of the tin using the parchment paper, and slice it into squares. Enjoy!