Preheat oven to 350 degrees F and spray a 9 by 13 pan with nonstick spray. You can also add parchment paper if you choose to do them that way. You can easily pull the entire batch of brownies out of the pan when they have cooled and then cut them.
You can also use a 9 by 9 pan but the brownies will be very thick and will need extra time to bake. I find they bake better in a 9 by 13 pan.
In a small saucepan on your stove, melt butter over low-medium heat. Add the chocolate and vanilla to the pan and stir until melted. Keep the heat low. Add your cocoa powder and whisk until all combined. Remove from the heat and set aside.
In a large mixing bowl add the eggs, brown sugar and regular sugar and mix together until well combined using a whisk. This will take a couple of minutes by hand.
Next, add the sourdough discard as well as the chocolate mixture and stir well.
Once you are done with that, add the salt, baking powder, flour and chocolate chips until just combined.
Pour the brownie batter into the pan and smooth out.
Bake in the oven for 35 minutes. Take them out of the oven and let them cool before cutting into them. These are so fudgy and gooey it is easier to handle them when they cool a bit.
You can store these in the fridge, freeze them in a container, or eat them all!