Lightly spoon flour into dry measuring cups; level with a knife. Combine flour and next 3 ingredients (through salt), stirring well with a whisk. Place butter and brown sugar in a medium bowl; beat with a mixer at medium speed until light and fluffy (about 1 minute). Gradually add flour mixture, beating at low speed. (Mixture will appear crumbly.) Sprinkle ice water over flour mixture; beat at low speed just until combined. Shape the dough into 2 (6-inch-long) logs; wrap each log in plastic wrap. Chill 1 hour or until very firm.
Preheat oven to 350°.
Line baking sheets with parchment paper. Unwrap dough; cut each log into 16 slices using a serrated knife. Place dough circles 1 inch apart on prepared baking sheets. Sprinkle tops evenly with turbinado sugar, gently pressing into dough. Bake at 350° for 18 minutes or until lightly browned. Remove from baking sheets; cool on a wire rack.
If you don't want to bake all of the cookies at once, freeze one dough log for up to two months. Slice frozen dough, and bake; if the dough is too hard to slice, let it stand at room temperature for 10 to 15 minutes.