Line an 8-inch square pan with parchment paper. Set aside.
In a large microwavable bowl, combine 1½ cups of white chocolate chips with ½ of the can of condensed milk and a pinch of salt. Microwave for 25 seconds and stir well. Reheat in additional 20-second intervals as needed until you get a smooth consistent texture, making sure to stir the mixture well in-between each interval.
Stir in ½ teaspoon of vanilla extract and 2 drops of red food coloring. Add additional drops of food coloring if desired to achieve a darker color.
Spread the mixture evenly into the prepared pan and allow to set for 30 minutes.
Add the remaining white chocolate chips and sweetened condensed milk to a large microwavable bowl with a pinch of salt. Repeat the process of microwaving in 20-second intervals until the chocolate has melted and has a smooth consistency. Stir in ½ teaspoon of vanilla extract.
Spread into the pan on top of the pink fudge layer. Immediately add valentine sprinkles, lightly pressing them into the top of the fudge if necessary to help them stay in place.
Chill until firm (about 2 hours). Cut into small squares.
Notes
Store in an airtight container at room temperature for up to 3 days, in an airtight container in the refrigerator for 2 weeks, or freeze for up to 3 months.