1. Heat the sweetened condensed milk and butter in a pot on low heat.
2. Add chocolate and allow to melt.
3. Using a wooden spoon or spatula keep mixing for 5-10 minutes without stopping. This will keep it from burning. Heat until it thickens like fudge (creamy but becomes difficult to stir).
4. If you have a thermometer make sure it goes 180-200F. The higher temperature will give you a harder brigadeiro.
5. Pour into a bowl and let cool. (4hrs)

Making the brigadeiros

1. Place the sprinkles/jimmies into a wide bowl.
2. Place a little bit of butter on your hands if the brigadeiro mix is too sticky and using a spoon, scrape a little onto your hand and roll it into a ball.
3. Drop it in the bowl of sprinkles and roll.
4. Place in a #4 cup (small white cups); this helps keep the shape the best.
5. You can store these for a long time; up to 3 months in the refrigerator or 5 months in the freezer. But make sure that you wrap very well in plastic container and plastic wrap.