Mill your flour into a small bowl and set aside.
In a large bowl add the butter and sugars. Using a hand mixer or a stand mixer, beat until well combined.
To that add the egg, molasses, vanilla, and sourdough discard. Beat again until well combined. Set aside.
Add the baking soda, cinnamon, ginger and salt to the bowl with your freshly milled flour. Stir to combine.
Add your wet ingredients to your dry ingredients, mixing in half before adding the other half. Do not overmix.
Cover with a towel or plastic wrap and allow this to rest in the fridge for at least 30 mins before baking. To further increase the benefits of the sourdough, transfer to the refrigerator for 12-24 hours.
When ready to bake, preheat oven to 350°F.
Line a baking sheet with parchment or a silicone baking sheet.
Using a standard sized cookie scoop or a spoon, scoop out dough balls roughly 1.5-2 inches.
Bake for 9-11 minutes depending on the size of your cookie balls.