Preheat oven to 350 degrees F.
In a bowl attached to a stand mixer (or with a hand mixer), cream together butter, coconut oil, and brown sugar until light. Add in eggs, water, vanilla and coconut extracts and beat until fluffy.
In a separate bowl, sift together dry ingredients: flour, salt, soda, cream of tartar. Slowly add dry ingredients to creamed ingredients and mix until just combined. Stir in shredded coconut.
Using a cookie scoop (I used a medium-sized one), scoop out dough onto cookie sheets, spaced 2-3″ apart. Bake for 10-12 minutes or until lightly browned around edges. Cool on tray for 10 minutes before transferring to wire rack to cool completely. Store in airtight container.