Western desserts - Chocolate Chip Cookies

Chocolate Chip Cookies

1/2 cup cold butter

1/2 cup brown sugar

1/4 cup white sugar

1 large cold egg

1/2 teaspoon vanilla extract

1 1/2 cups flour

1/2 teaspoon baking powder

1/4 teaspoon baking soda

Salt

1 1/2 cups chopped dark chocolate

2/3 cup chopped white chocolate

1/2 cup chopped walnuts

Pinch of coarse salt