Line an 8x8 pan with parchment paper and spray it lightly with nonstick baking spray.
In a large microwave-safe bowl, combine the sweetened condensed milk and white chocolate. Place it in the microwave and cook for 1 minute.
Stir the mixture together. If the chocolate hasn’t fully melted, microwave it for an additional 30 seconds.
Stir in the vanilla extract and transfer the fudge to the parchment-lined pan. Spread it out evenly using a spoon or offset spatula. If you want to decorate your fudge with sprinkles, make sure to add them while the fudge is still soft.
Place the fudge in the fridge to chill for at least 4 hours, or up to overnight.
Remove the fudge from the fridge and slice it into your desired size. Serve slightly chilled.
Store any uneaten fudge in the fridge in an airtight container for up to 3 days.
This recipe requires about 5 minutes of prep time. You will want to chill the white chocolate fudge for about 4 hours prior to serving.