Copycat Famous Levain Bakery Chocolate Chip Cookies

Ingredients

• 1 cup cold butter cut into small cubes
• 1 cup brown sugar
• 1/2 cup sugar
• 2 eggs
• 1 1/2 cups flour
• 1 1/2 cups cake flour
• 1 teaspoon cornstarch
• 3/4 teaspoon baking soda
• 3/4 teaspoon salt
• 1 1/2 cups semi-sweet chocolate chips
• 1/2 cup butterscotch chips
• 2 cups walnuts roughly chopped