In a mixing bowl, combine the softened butter and brown sugar.

Add in two eggs, vanilla extract and sourdough starter and mix until combined.

Next, add all of the dry ingredients to the mixer and beat until thoroughly incorporated.

Add the chocolate chips and mix briefly until just incorporated.

Place the dough into the fridge for at least 1 hour but up to 2 days.

When ready to bake, preheat the oven to 350 degrees. While the oven is preheating put the cookie dough into a pie plate. Using an offset spatula or clean hands, press the dough into the pie plate.

Bake at 350 for 33 to 35 minutes. (Note that “officially” the temperature of cookie dough to be done and considered safe is 175-185 degrees.) Let the cookie pie rest until fully cooled. The pie will continue to cook slightly due to the residual heat and this helps it to fully set.

Let the cookie pie cool completely prior to serving and enjoy!