Line an 8×8-inch square pan with parchment paper.
Add the white chocolate chips and sweetened condensed milk to a microwave-safe bowl.
Microwave in 20–30 second intervals, stirring thoroughly after each interval, until completely melted and smooth.
Add the creamy peanut butter and stir until the mixture is uniform, thick, glossy, and completely combined.
Pour everything into the lined pan, spread it into an even layer, and refrigerate for about 2–3 hours, or until firm.
Lift it out using the parchment and cut into small even squares.
