Line an 8 or 9-inch square pan with parchment paper. First spraying the pan with cooking oil, then lining with parchment paper, extending paper over edges of pan. The cooking oil helps the parchment paper to stick to the pan.
In a medium saucepan, add sweetened condensed milk and 1/2 cup peanut butter over medium heat. Cook stirring constantly until just bubbly, about 7-9 minutes. It is ready once the milk and peanut butter start to bubble and thin a bit.
Turn of the heat and stir in white chocolate chips and vanilla until smooth. Spread into prepared pan.
Heat the 2 Tablespoons peanut butter in the microwave to soften it a bit more. Then add dollops randomly in the pan. Using a butter knife quickly swirl the peanut butter into the fudge.
Tap the bottom of the pan against the counter to smooth it out a bit. Cover and refrigerate.
Chill for 2 hours, then remove from pan by lifting the parchment paper. Cut into 20 squares and serve!