Preheat oven to 350 degrees F. Liberally grease a casserole 13x9" baking dish with cooking spray or butter. Set aside.
In a large bowl, add in the creamy peanut butter. Gradually add in the milk, whisking constantly and carefully, to combine. Mixture will smooth out somewhat. Add in the beaten eggs, vanilla extract, pinch of salt and sugar and whisk to combine. Mixture will be smooth and runny. Add in the bread and toss to coat. Cover and refrigerate for 20 minutes, stirring at the 10 minute mark.
Once bread has soaked some of the liquid mixture, spread 2/3 of the bread mixture into the prepared pan. Top with the entire first can of pie filling, gently swirling it on top of the PB bread mixture. Top with the remaining bread mixture, and lastly, top with the remaining entire can of pie filling, gently swirling it into the PB bread mixture.
Cover the pan with foil and bake for 15 minutes. Remove the foil and continue baking for 35-45 minutes (mine cooked about 40 minutes) or until golden brown and just about set. Remove from the oven and sprinkle with chopped peanuts. Let set for 5-10 minutes before cutting into squares. Store covered in the fridge.