Line an 8-by-8-inch square baking pan with aluminum foil. Spray the foil with cooking spray.
In a medium saucepan over low heat, combine the chocolate chips and sweetened condensed milk and stir until it's all melted and smooth. Pour it into the prepared pan and spread to even out the surface. Sprinkle on the crushed candies. Refrigerate for 2 hours.
Lift the foil out of the pan and peel off the fudge. Cut into small squares.