Line an 8"x8" baking pan with foil, leaving a 2" overhang over sides. Set aside.
In a medium heatproof bowl, add milk chocolate chips.
Fill a medium saucepan with about two inches of water and place over medium-low heat. Place the bowl over the saucepan and let the chocolate chips melt, stirring frequently until it is melted and smooth about 5-10 minutes.¹
Remove bowl from heat. Stir in sweetened condensed milk, vanilla extract, and Fireball Cinnamon Whiskey to the melted milk chocolate; mix until incorporated.
Pour mixture into the prepared baking pan, spreading evenly. Refrigerate for 3 hours or until firm. Use the foil overhang to remove from pan. Cut to the desired size. Eat & Enjoy!
Store Fireball Fudge in an airtight container; will keep 10+ days.¹ These instructions use the double boiler method for melting the chocolate.