Over meduim heat, melt butter in non-stick pan.
Stir in cocoa powder and salt.
Stir in condensed milk and vanilla.
Continue to stir over medium heat for about 10 - 12 minutes, until a thicker fudgy consistency.
Remove from heat and poor fudgy mix onto a plate. Let cool slightly. Roll in balls and then roll in chocolate sprinkles. Keep in fridge.