I made these using Martha White strawberry cheesecake muffin mix. The cookies had a fluffy, cake like texture. I used the mini scoop - I think I would try with margarine and swapping out baking soda for the baking powder.
I had more brownie mix left over than PB. I increased chips to 100g; 85g milk chocolate, 15g mini semi-sweet chocolate. I used the small scoop to scoop 2 and then rolled them together. I cut in half and then flipped the cookies to create a swirl. Next time, try to add peanut butter chips to the peanut butter side. Freeze in balls. Before cooking, let thaw while the oven preheats. 350 for 6 minutes, flip and 6 minutes more.