Line a 9x9 pan with aluminum foil and spray very well with cooking spray.
In a small saucepan on low heat, add the sweetened condensed milk, all chocolate chips and butter. Melt everything together until smooth whisking constantly to prevent scorching the bottom. Once everything is thoroughly combined, stir in vanilla and fold in candy corn by hand. Pour mixture into prepared greased pan and spread out into an even layer. I spray the top of my rubber spatula with cooking spray to prevent sticking and help it spread easier with less work.
Cover fudge with plastic wrap and place in the fridge for up to 2 hours or until firm. Cut into squares and serve.
Fudge will stay fresh stored in an airtight container for 3-4 days kept in the refrigerator. Remove from refrigerator 30 minutes before serving to give it time to soften up a little bit.