Step 1
In a medium saucepan over medium heat, add the condensed milk.
Step 2
Add cocoa and butter.
Step 3
Cook, stirring, until the mixture thickens, about 7–10 minutes.
Step 4
Remove from heat and let sit until the mixture cools enough.
Step 5
Roll small balls.
Step 6
Decorate them by rolling in various coatings (e.g. coconut flakes, powdered sugar, chopped nuts, chocolate or colored sprinkles).