Cook for 4-5 minutes stirring as it thickens. It is done when a spatula scraped along the bottom leaves a trail for 3-5 seconds. Remove from the heat.
Butter a shallow dish and pour the chocolate into the dish. Place in the refrigerator to cool for 15-20 minutes or in the freezer for 10 minutes.
Once the chocolate has firmed up and cooled, scoop a tablespoon of it up and then roll it into a ball. Roll the brigadeiro in sprinkles and then place in mini cupcake paper liners.