Adjust oven racks to the 2 middle positions and preheat oven to 350 degrees F (175 degrees C). Line 2 large baking sheets with parchment paper. Set aside.
In a medium bowl, whisk together flour, baking soda, cream of tartar and salt. Spoon your flour into your measuring cup, don’t scoop. Better yet, invest in a scale. Set aside.
Cream together the butter, white sugar, and brown sugar until smooth, a couple minutes. Add vanilla and water then beat in the eggs one at a time. Drop by large spoon-fulls onto parchment paper.
Cookies can be stored in an airtight container at room temperature for up to 5 days, and frozen for up to 1 month. Freeze your baked cookies on the baking sheets lined with the parchment paper first, until firm, and then transfer them to a freezer bag or another airtight container.
When ready to serve take frozen baked cookies out of their containers and place them on a paper towel-lined plate to thaw at room temperature.
Spoon your flour into your cup, don’t scoop. Better yet, invest in a scale.