Melt the butterscotch chips in a microwave-safe bowl on 20-second intervals, stirring between each interval. Set the melted butterscotch aside to cool slightly for about 3 minutes.
In the bowl of a stand mixer fitted with the paddle attachment, beat together the cream cheese and egg yolk until well combined. Beat in the melted butterscotch. Add dollops of the the cheesecake mixture and reserved brownie batter alternately on top of the brownie batter in the pan. Using a knife or toothpick, swirl the cheesecake mixture and brownie batter together.
Bake the brownies for about 30 minutes, or until a toothpick inserted comes out with a few crumbs. Remove the brownies from the oven and let them cool completely before lifting the parchment paper out of the pan. Cut the brownies into 12 or 16 squares and serve.
★ Did you make this recipe? Don't forget to give it a star rating below!