Preheat to 350 degrees.
In a stand mixer with paddle attachment, cream butter, brown sugar and granulated sugar together for a few minutes until light and fluffy. Scrape down the sides on occasion to fully incorporate all ingredients.
Add the eggs in one at a time and mix until well incorporated.
Add vanilla and sourdough discard and mix until just combined.
In a separate bowl, combine the oats, flour, baking soda, baking powder, cinnamon and salt.
Add the dry ingredients to the wet ingredients about ⅓ at a time, then mix until just incorporated.
Fold in raisins and gently combine them into the dough.
Spoon onto a parchment lined baking sheet and bake for 10 minutes or until the edges begin to turn golden.
