I got this recipe from Two Peas and Their Pod a while back. It is one of the BEST cookie recipes I have ever gotten. If you like chocolate, peanut butter, and nuts, then these are a must try cookie. They were so wonderful out of the oven, can't eat the nuts, but when they came out a little piece fell off without nuts and I tried it. Oh my goodness, it was so good! I put them by the spoonful on the first sheet. They didn't flatten at all. Very nice. The next sheet I flattened them a little with my fingers and they were nice too. Just which ever way you like them. I liked them both ways.
Preheat oven to 350 degrees. Line two baking sheets with parchment paper. Set aside.
In a medium bowl, whisk together the flour, baking soda, baking powder, and salt. Set aside.
In the bowl of a stand mixer, beat the butter and the peanut butter together until fluffy. Add the sugars and beat until smooth. Add the egg and mix until combined. Add the milk and the vanilla extract and mix again.
Drop by tablespoons onto prepared baking sheets. I also sprinkled a little salt on top. (0ptional) I didn't press them down, and they spread out very little, if at all.
I gently flatted the next sheet, and they were nice also. Only flatter, but still a thick cookie. I like them both ways.
It says to bake 10-11 minutes. Mine took exactly 10 minutes.
Cool the cookies on the baking sheets for about 5 minutes, then remove to a rack to cool completely.
Recipe says yields 3 doz. I got 3 doz + 9 and they were a nice size, not small.
Just an update to my cookies.....I purchased a couple silicone baking sheets and used them today when I made these cookies. The first batch came out flat as a pancake! So I went back to my parchment paper and they were fine. Hum.....I don't know why. Anyway if you don't mind flat cookies it won't matter. I like them a little puffy for myself. But everyone's different. Just wanted you to know. Thanks!