Flourless Brownie Cookies
Makes about a dozen

1/2 cup softened butter 
1/2 cup brown sugar
1/2 cup white sugar
1 egg
1 teaspoon vanilla
1/2 teaspoon baking soda
1/2 teaspoon salt
1 cup cocoa powder
1/2 cup white chocolate chips
1/2 cup semi-sweet chocolate chips
1/2 cup walnuts (optional)

Preheat oven to 350ºF. Mix together the butter and sugars. Add the egg and vanilla and mix until combined. Mix together the soda, salt, and cocoa and add to the wet ingredients, mixing until combined. Stir in the chocolate chips and nuts. Bake for about 10 minutes or until they look done.