Line 8x8 baking dish with parchment paper leaving a 1-inch overhang on the sides. Lightly mist parchment paper with non-stick cooking spray. Set aside.
Add sweetened condensed milk, butter and chocolate chips to a large microwave safe bowl. Microwave for 1 minute, stir and microwave 30 additional seconds in intervals until fully melted.
Once the chocolate is melted, stir in vanilla.
Pour the fudge into your prepared baking dish and spread evenly, smoothing the top with a rubber spatula.
While the fudge is still wet, sprinkle holiday sprinkles and flaky salt onto the top.
Place in the fridge to set for a minimum of one hour.
Once the fudge has set, remove from the baking dish onto a cutting board. Using a sharp knife, slice into even squares and serve. Enjoy!
Notes
If you don't want to use the microwave, you can melt the chocolate chips over a double boiler. This may take a bit more time, but it does work wonderfully.
You can also use any other cooking chocolate for this recipe if you don't have chocolate chips. I would recommend using a high quality chocolate like Callebaut to get that perfect rich chocolate flavor.
Use room temperature butter for this recipe, and whisk the mixture properly to make sure there are no blobs of butter that haven't incorporated into the mixture.
Keep whisking the mixture at every 30 second interval and stop when the chocolate melts. Overheating the chocolate will cause it to seize and will turn grainy.