In a medium bowl, whisk together the all-purpose flour, ground turmeric, ground ginger, baking soda, baking powder, and salt.
In a large mixing bowl, use an electric mixer or whisk to cream the softened unsalted butter with the brown sugar and granulated sugar until light and fluffy, about 2 to 3 minutes.
Beat in the large egg and vanilla extract until fully incorporated.
Gradually add the dry ingredient mix to the wet ingredients, stirring gently until just combined. Avoid overmixing.
Gently fold in the chopped crystallized ginger.
Using a cookie scoop or tablespoon, scoop out dough balls and roll each one into the 1/2 cup granulated sugar to coat completely.
Place the sugar-coated dough balls on a parchment-lined baking sheet, spacing about 2 inches apart. Bake at 350°F (175°C) for 10-12 minutes until edges are crisp and centers set but chewy.
Allow the cookies to cool on the baking sheet for 5 minutes before transferring to a wire rack to cool completely.