Roughly chop the chocolate bars into smaller pieces and transfer them to a large heat-proof mixing bowl.
Heat the heavy cream and butter. Then add the heavy cream and butter mixture into the chopped chocolate.
Stir with a spatula until the chocolate has melted and is well combined.
Refrigerate for 5-6 hours to set the chocolate or freeze for 2 to 3 hours.
Using a sharp knife cut the chocolate into 1-inch squares. Dust the sliced chocolates with cocoa powder.