In a medium size sauce pan over medium-low heat, add the unsalted butter and condensed milk, mix well.
Gradually heat the mixture with constant stirring until it comes to mild simmer.
Sieve through the cocoa powder into the mixture, keep stirring until all cocoa powder is dissolved without lumps. Add the vanilla extract.
Continue the stirring so that to avoid burning of the mixture, also remember the scrape the bottom and also the sides regularly with a spatula.
For around 12 to 18mins (time vary from different pan and stove, we suggest to use a wide and shallow pan to reduce the time needed), the mixture will become thicken and not too sticky to the pan, your brigadeiro is ready.
Remove from heat and set it aside to cool down until the temperature fine enough for your hands to handle.
Roll into small balls (19 g each) and cover the balls with the toppings of your choices.
