Line an 8 x 8 in pan with foil.
Heat the chocolate chips and sweetened condensed milk over medium heat, stirring frequently, until chocolate is melted and everything is well combined.
Remove from heat and add in the vanilla, cinnamon, salt, and cayenne. Mix well.
Pour the fudge into the prepared pan immediately. Refrigerate for at least 4 hours.
Cut into 16 squares and enjoy.