Grease a clean plate with a little butter to prevent sticking, and set it aside.

Melt 2 tablespoons of butter in a nonstick skillet over medium heat. Stir in 1 cup of cocoa powder and 1 can of sweetened condensed milk, mixing well for about 10 minutes until thick.

Transfer the mixture to the greased plate and flatten it into an even layer about half an inch thick. Allow it to cool at room temperature, then refrigerate for at least 2 hours until firm.

Butter your hands lightly and roll small amounts of the mixture into smooth balls, about the size of a cherry.

Coat each ball in colorful sprinkles and place them back on the greased plate.

Serve the Brigadeiros on a platter or enjoy them individually as a treat.