Line a 9x13 baking dish with parchment paper and spray with non-stick spray. Set aside.
Using a heat safe bowl, melt the white chocolate chips for 30 seconds in the microwave.
Stir the chocolate and continue to cook for 20 seconds at a time until the chocolate is completely melted.
Once melted, add the peanut butter to the white chocolate and stir together until well combined.
Pour the chocolate peanut butter mixture into the prepared baking pan. Using a spatula, push the chocolate to the edges of your pan.
In another heat safe bowl, melt the semi sweet chocolate chips for 30 seconds in the microwave. Stir the chocolate chips and cook again for 20 seconds until the chips are melted.
In a random swirly pattern, pour the semi sweet chocolate all over the top.
Then, run a knife or a skewer through the chocolate to create a pretty swirl pattern.
Set into the fridge for several hours to harden, cut into bars and enjoy! Keep stored in the fridge to prevent any melting.