Preheat oven to 350 degrees F (175 degrees C). Grease cookie sheets.
In a medium bowl, sift together the flour, baking powder, baking soda and salt. Set aside.
In a large bowl, cream together the butter, brown sugar and white sugar until smooth. Beat in the eggs one at a time, then stir in the vanilla. Gradually blend in the sifted ingredients.
Stir in the oats and macadamia nuts. Drop by rounded spoonfuls onto the prepared cookie sheets.
Bake for 10 to 12 minutes in the preheated oven. Allow cookies to cool on baking sheet for 5 minutes before transferring to a wire rack to cool completely.
Interesting Facts
Macadamia nuts are the highest source of monounsaturated fat of any nut.
Oats are a great source of fiber, vitamins, minerals, and antioxidants.
Cookies are believed to have originated in the 7th century in Persia.