Melt with low heat the condensed milk, the chocolate and the butter
When everything will be melted, add the orange peel
Cook still for 15 minutes
Let the mixture cool down in refrigerator for at least 3 hours
When it will be thickened, take little portions out of the truffle mass and work them with your hands (you can butter them so that the process would be easier) till they will be round shaped
Put the truffles in a bowl where you had previously put cocoa powder
Roll the chocolate balls in the cocoa powder till full coverage
Recipe by The Adagio Blog at https://adagioblog.com/brigadeiro-orange-chocolate-truffles/