Whisk together flour, baking powder, baking soda, and salt in a medium bowl and set aside. Preheat oven to 375F.
In a bowl of a standup mixer, cream together the sugars and butter. Add in the eggs and vanilla and beat well. Slowly add the flour mixture and continue to mix in batches. Stir in the coconut, oats and walnuts.
Using a 1 1/4" cookie scoop, drop small balls on an ungreased cookie sheet spacing 2" apart. Bake for 12-14 min. or until golden brown. Cool on cookie racks. Store in airtight containers. Will freeze well.