Preheat oven to 350 degrees and line two baking sheets with parchment paper
Using a medium bowl, whisk together the flour, ginger, cinnamon, nutmeg, all spice, kosher salt and baking soda until combined
Using a stand mixer, beat together the butter and brown sugar until combined and fluffy
Beat in the molasses until combined
Beat in the egg and vanilla until combined
Gradually beat in the dry ingredients until a dough forms
Pour the white sanding sugar into a small bowl
Using a mini ice cream scooper, scoop some dough out and roll into a ball
Roll the dough into the white sanding sugar
Repeat the steps until all balls are formed and coated
Place the cookie dough balls onto the prepared baking sheets
Using the back of a teaspoon or small spoon make an indent into the cookie dough balls
Bake in the oven for 8-10 minutes
Remove from oven and allow to cool for a few minutes
Place a Ghirardelli milk chocolate wafer into the indent of the cookies
Allow the cookies to cool for another 30 minutes before enjoying!