Heat 8oz of the chopped chocolate and coconut oil over a double boiler. When the chocolate just becomes melted, immediately remove from heat and add in remaining 4oz of chocolate, stirring until the chocolate is completely smooth.
Pour the chocolate mixture on a cookie sheet lined with wax paper. Smooth the chocolate with a spatula until it is about ¼ inch thick.
Now for the fun part… gently sprinkle the toppings onto the melted chocolate as desired. Pop it in the freezer for a few minutes, until set. Break off a piece and enjoy!