Preheat oven to 350℉. Spray a 3 quart baking dish with olive oil spray or non-stick cooking spray.

Place torn bread in a large bowl and set aside.

On a rimmed baking sheet, toast pistachios for 8-10 minutes. Shake pan halfway through. Once cool, chop and toss into the bowl with bread. Toss dried cranberries in at this time too.

In a large skillet, cook sausage for 8-10 minutes or until browned and cooked through. Transfer to the bowl of bread with a slotted spoon.

In the same skillet, add the chopped onion, apple, celery, and fennel. Sprinkle in the pinch of salt and black pepper. Stirring often, cook ingredients until onion is nice and soft which will take about 10 minutes. Transfer mixture to bowl with the bread.

With heat on medium, pour in the apple cider vinegar. Scrape up browned sausage bits and cook for 1-2 minutes. Add 1/2 cup butter, stirring constantly. Once butter has just melted pour over bread mixture. Mix bowl contents well with a large wooden spoon. Transfer to prepared baking dish.

In a medium bowl, whisk together the eggs and chicken stock. Pour eggs over the bread mixture evenly in attempt to saturate all of the bread. Stir up ingredients in baking dish a few times.

With the remaining 1/4 cup melted butter, dot the top of mixture.

Cover baking dish with a greased piece of foil and bake for 30 minutes.

Uncover baking dish, increase oven temperature to 450 and bake for an additional 15-20 minutes. Keep and eye on it at this point and if it seems to be getting too brown on top, decrease oven temp to 400℉ and place foil back over dish.

Let sit for 10 minutes prior to serving.