Prepare the butter pecan cake according to the package instructions.
Cool in the pan completely.
Assemble the Rum Balls
Crumble up the baked cake into a medium mixing bowl.
Add in the rum and the condensed milk. Mix together until all of the ingredients are combined and the cake is now a dough that can be rolled into balls.
Roll the mixture into one inch balls, then roll the balls into the chocolate sprinkles, covering them completely.
Place the rum balls on a parchment lined baking sheet. Freeze them individually first, then transfer to a sealed container to keep frozen.
These are best if left to sit a few days in the refrigerator if you are eating them soon, or keep them in the freezer until you are ready to eat.