Brian and I got into a discussion on twitter about creaming peanut butter. We both thought it was possible, but disagreed on how much it would blow up my stand mixer. I decided to run a test. I would make two batches of peanut butter cookies, using identical recipes. One I would cream, one I would not. I would bake them side by side and see which rose more.
I started with one cup of peanut butter. For the creamed version I started beating on the 8 setting. And added 1 cup of sugar, one tablespoon at a time.
Once that was all incorporated, I added in one egg and 1 teaspoon of vanilla extract.
For the non-creamed version I added in the same amount of all the ingredients, but just mixed by hand.
There was already a stark contrast between the two. The creamed dough was much stiffer.
I measured out six 40 gram balls of each of dough and placed them side-by-side on a baking sheet. I baked it at 375 for about 16 minutes.
Creamed dough is on the left, non-creamed dough on the right. The non-creamed dough was much more even, more evenly cooked, and tasted a little better. Neither rose appreciably, and neither rose more compared to the other.
If you want the fluffy peanut butter cookies that you often see with hersey kisses in the middle, there are tricks to use. First, add shortening or butter to the peanut butter, it makes it a better target for creaming. You can also add flour to the batter to get some gluten development and a better matrix to trap air bubbles during the baking.
In the end, they were both tasty, but the simple mixed version was a little better, mostly because the dough was less stiff.