In a medium saucepan over medium-low heat, melt the butter. Add the condensed milk and cocoa powder. Cook the mixture until it thickens enough so you can clearly see the bottom of the pan when stirring, about 15 minutes. The consistency should be firm enough to stay together. Pour it directly into a dish and let cool to room temperature, about 15 minutes.
Lightly grease your hands with butter and roll about a teaspoon of brigadiero between your palms to form 1 1/2-inch balls.
Roll them in your favorite chocolate sprinkles and place them into small paper cups.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.