Peanut Butter Sandwich Cookies

I did not feel great after work today, so when there was a knock on my door not long after coming home, I didn't really want to deal with it. However, when I saw that it was my baking buddy from down the hall, I had to answer the door.
"Hi! So, my friend is kind of being a jerk right now. Can we bake something?"
I hestitated for a moment; my head was pounding and my unfolded laundry was screaming at me from the couch.
"Of COURSE! I have to warn you though, I'm out of chocolate chips," I told him.
"That's ok! Remember those REALLY good peanut butter cookies you made that one time? I was thinking we could make those." That was like 4 months ago...steel trap memory, that one has. And actually, I'm thinking he might be telepathic, because I had some leftover peanut butter frosting in the fridge I wasn't totally sure what to do with...these cookies would be perfect.
So, we baked. And he is quite the baker. Ever so carefully measuring out all the ingredients, he spilled a little baking soda and apologized profusely. 
In addition to having impeccable manners, the kid is quite the story-teller. I heard all about Halloweens past, his spoiled friend with the half-pipe in the backyard, and rockets he made out of soda bottles.

The cookies turned out great, and he even got to master a new skill: piping frosting out of a bag.  As the cookies came out of the oven, my headache was gone and I was in much better spirits.  Thanks, baking buddy!

(adapted from Mrs. Fields Best Cookie Book Ever)

Cookies

1 1/2 cups flour

1/2 tsp baking soda

1/2 tsp cinnamon

1 cup quick oats

1 cup light brown sugar

1 stick butter, softened

1 large egg

1 tsp vanilla

Whisk together flour, baking soda, cinnamon, and oats in a medium bowl.

In a separate bowl, cream the butter and brown sugar until fluffy.

Beat in vanilla and egg, then stir in dry ingredients until just combined.

Roll about 2 tsp of dough into a ball, then flatten and press onto a Silpat-lined baking sheet.

Repeat with remaining dough.

Bake at 350 for 8-12 minutes (closer to 8 for softer cookies, closer to 12 for crisper cookies).

Cool on a wire rack.

Filling

You could use any peanut butter frosting...or this (but you will likely have some left over)

3/4 cup creamy peanut butter

1/4 cup butter, softened

2 tbsp half and half

1 tsp vanilla

1 1/2 cups powdered sugar

Beat all ingredients together in the bowl of an electric mixer until smooth.

When cookies are cool, pipe or spread frosting on one and press another on top to make a sandwich.