In saucepan over medium heat combine sweetened condensed milk, unsweetened cocoa powder, butter, and salt.

Cook, stirring occasionally until mixture thickens and begins to pull away from sides of the saucepan, about 10 minutes.

Remove from heat, transfer to a bowl, cover with plastic wrap and place in fridge to chill for 30 minutes or overnight.

Spread powdered sugar on a plate. Lightly spray hand with non-stick cooking spray. With a spoon scoop out heaping tablespoon of chocolate mixture and with hands roll into smooth ball, then roll into powdered sugar until lightly coated. Place Brigadeiro on plate, chill until ready to serve.