1/2 cup peanut butter
1/2 cup granulated sugar
1/2 cup packed brown sugar
1/2 tsp baking soda
1/2 tsp baking powder
1 egg
1/2 tsp vanilla
1 1/4 cups flour
1/4 cup mini marshmallows, cut in half.
Preheat the oven to 375 and line a baking sheet with parchment paper. Beat butter and peanut butter until combined. Add the baking soda, baking powder and both sugars, beat until combined. Beat in the egg and vanilla, until combined. Beat in the flour (by hand is easiest, it will be a very stiff dough). Fold in the marshmallows. Roll generous tablespoons of dough into 1" balls and place them on the prepped sheet. Bake for 7-9 minutes, let cool on the tray for a minute or two then transfer to a cooking rack.
(adapted from BH&G Ultimate Cookie Book or UCB)
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Ok, you ready? Here is the deep, meaningful back story to these cookies. I wanted to bake something and I didn't want to leave the apartment. I had peanut butter and marshmallows. That's it. I didn't even scour the nets for a recipe. I still haven't made that many cookies from the UCB, which I got for Christmas, so I decided to step away from my go-to recipe and try out their classic peanut butter cookie. The marshmallows were the only adaptation from me, but they turned out wicked good. It's a good recipe, different levels of butter (my go to has half shortening, making them crispier) and different ratios of baking soda/powder made these a little thinner. I think. Well, I know they are thinner, but I don't know for a fact that that's why. Anyway, they are quite good, I think I like the slightly chewier and more buttery flavor of all butter over half and half with shortening. Let's make these things.
Pretty standard cookie making here. First I mixed the butter and peanut butter.
Added the sugars, baking powder and soda.
More mixing. Egg and vanilla,
mix again. 
Now the flour. 
The recipe said add it a bit at a time, using an electric mixer. Once it started getting hard on the mixer it said to stop and use a spoon. I said screw all that and did the whole recipe by hand. Because I'm like that. So I just dumped it all in, mixed it up 
and folded in the marshmallows. 
I didn't have minis, those would have been easiest. I had the bigguns and I cut them into half inch pieces. Or so. Then I rolled them into 1" (or so) balls 
and made an attempt at crosshatches. 
The marshmallows made that tricky, but it worked well enough. Then baked for 7-9 minutes and out. 
Lovely. You want to let them sit for a minute before trying to move them. Otherwise the marshmallow will be too liquid and the cookies too soft and it will just be a disaster. Crap, I should have taken a picture of that. But I ate it. Oh well. I liked the way the marshmallows toast up, it adds a nice level of flavor. So next time you want something that's familiar but a little but different or don't feel like leaving the house to get more ingredients, give these a shot. 
Now, when I'm making peanut butter cookies I always use chunky peanut butter. I like the texture the extra peanut bits gives. But I've known people who will only use smooth. What kind do you folks use when you make peanut butter cookies?
