Melt the butter and sugar on low heat, keep stirring until the sugar melts. Add the chocolate, broken into pieces, and after it melts remove the mixture from the heat.
Put the forms in an oven dish or tray and put them in the freezer for at least 1 hour. Next, put them in a preheated 428°F (220 °C) oven for 10-12 minutes to bake.
Once you see that they've caught a nice crust on the top and sides, they're done. Allow them to cool in the forms. Usually, you can get them out of the forms without a problem.
You can sprinkle powdered sugar on top or use cookie cutters to get the desired shapes. Keep in the refrigerator before serving. Enjoy!