In a medium mixing bowl, combine the butter and sugars. Cream together. Add the vanilla extract, stirring until incorporated.
Add 3 tbsps of water to a small bowl, and stir in the baking soda.
One tablespoon at a time, mix the water-baking soda mixture into the butter-sugar mixture, mixing well after each addition.
Stir in your sourdough discard. Do NOT eat the raw cookie dough after you add this in!
Add the ground oats, all purpose flour, baking powder and salt. Mix until dough comes together. Lastly stir in the chocolate chips.
Using a large cookie scoop (or 1 tbsp size balls), place on cookie sheet 2 inches apart.
Bake for about 12 minutes, or until cookies are golden and just set. Allow to sit on pan for a few minutes then serve warm!