Step 1

Grease an 8-inch square pan with nonstick spray and set aside. (If desired, line the pan with parchment or plastic across the bottom and up the sides for easy release.)

Step 2

To a large heatproof bowl, add the condensed milk and chocolate chips and microwave in 30-second intervals, stirring with a silicone spatula between each, until the chocolate is melted and the mixture is smooth, 1–2 minutes. Stir in the vanilla and salt until fully incorporated, about 30 seconds.

Step 3

Scrape the mixture into the prepared pan, using the spatula to smooth the surface and spread into an even layer all the way to the sides and corners. Refrigerate until set completely, 1–2 hours.

Step 4

Slice the fudge into pieces and serve. (The fudge will keep in an airtight container at room temperature or in the fridge for up to 1 month.)