Combine the white chocolate chips and peanut butter in a microwave safe bowl and microwave in 30-second increments, stirring after each, until completely melted.
Stir the Rice Krispies into the peanut butter/white chocolate mixture. Let the mixture sit and cool about 10 minutes, stirring occasionally.
Gently stir in the miniature marshmallows and chocolate chunks
Pour the mixture into the prepared pan and press into an even layer. Refrigerate until set, about 15 minutes.
Remove from the pan and cut into squares. Store in an airtight container in the refrigerator for up to 1 week.
