Preheat oven to 350 degrees F.
Line 8×8 inch pan with nonstick foil.
In a bowl, melt butter in the microwave.
Stir in chocolate chips until most have melted.
Add flour, salt and both sugars.
Add eggs, yolk and oil.
Stir well and fold in the chocolate chunks.
Pour in pan and bake 35-40 mins.
Chill for clean cut brownies