To prepare a thick and chewy peanut butter chocolate chip bars recipe, first you need to prepare your ingredients. First, you'll need your chocolate chips. You can find them at your local grocery store, or you can buy them online. Then, add your dry ingredients to the wet ingredients and mix them together until they're well combined. Now, it's time to make the bars. Preheat your oven to 350 degrees F (180 degrees C) and grease and flour two 9x9x2-inch baking pans. Set aside. In another bowl, mix together the flour, cocoa, baking powder, salt, and baking soda. Pour the dry mixture into the chocolate mixture and stir until the mixture is evenly coated. Next, stir in the melted chocolate until it is fully incorporated. Add the chopped peanuts and toss to coat them evenly. Finally, pour the batter into your prepared pan and bake for 20 to 25 minutes. Remove from the oven and let cool.