1. Line a 9×9 square pan with parchment paper that covers the sides of the pan.
2. Place the chocolate chips and sweetened condensed milk in a large bowl and microwave for one minute. Stir well to combine and allow the heat to melt the chocolate chips. If needed, microwave for another 30 seconds or so, until the chocolate is completely smooth.
3. Stir in the vanilla extract, then quickly transfer the mixture to the lined pan and spread evenly.
4. Refrigerate the fudge until firm, 2-3 hours.
5. Cut the fudge while it’s still cold (right out of the fridge) and store in an air tight container. Fudge can be stored at either room temperature or the fridge. It will be softer at room temperature.