Preheat oven to 375 degrees
Line a 9”x13” baking pan with parchment paper or foil including sides so brownies can be lifted out after baking. If you use foil you will also need to spray the foil with a non-stick spray.
In a medium-sized saucepan combine sugar and butter. Cook over medium heat, stirring often until butter is melted and sugar has dissolved.
Remove from heat and let it sit to cool slightly.
Once it has cooled slightly add the 2 eggs and vanilla, whisk mixture well.
In a small bowl, combine flour, baking powder, and salt.
Add flour mixture to sugar mixture and stir to combine.
Fold in butterscotch chips then spread into prepared pan.
In a small bowl beat cream cheese with the egg yolk then add Nutella and mix until creamy.
Drop spoonfuls of Nutella mixture over batter in baking pan.
Swirl Nutella mixture through brownie mixture being careful not to scrape the bottom of the pan.
Bake for 25 minutes or until a toothpick inserted comes out clean.
Remove from oven and cool on a wire rack.
When brownies reach room temperature lift them from the pan holding onto the edges of parchment paper or foil.
Cut into squares. Enjoy brownies at room temperature or chilled.
Store brownies in refrigerator or freezer.