Peanut Butter Cup Baked S'mores

We had our second annual end of the school year/beginning of summer barbeque at our house.  It's a nice way to start the summer.  Kevin does the barbequing and I do the sides and dessert.

I went with the summer time theme and made another s'more treat.  This time I used peanut butter cups instead of plain chocolate.  These are by far my favorite baked s'more that I have made. 

Peanut Butter Cup Baked S’mores 
From: Mels Sweet Life (adapted from Pinch of Yum and Sprinkle Some Sunshine)

Ingredients
1/2 cup butter, softened
1/2 cup packed brown sugar
1/4 cup sugar
1 egg
1 teaspoon vanilla
1 1/4 cups flour
1 teaspoon baking powder
1/4 teaspoon salt
1 cup graham cracker crumbs
16 peanut butter cups
1 1/2 cups marshmallow fluff*

This is not marshmallow topping. See previous post about fluff.

Directions

1. Preheat the oven to 350 degrees.  Line an 8×8 baking dishing with parchment paper; coat lightly with cooking spray.
2. In a large bowl of the bowl of stand mixer, beat butter and sugars until fluffy.  Beat in egg and vanilla until combined.  Scrape down the sides.  With the mixer on low, stir in the flour, baking powder, salt, and graham cracker crumbs until mixed.
3. Spread 2/3 of the dough on the bottom of the prepared baking dish.  Lightly press the peanut butter cups into the dough, then spread marshmallow fluff on top.  Press the remaining dough on a non-stick surface into the shape of an 8×8 square.  Place the square on top of the fluff and press down lightly.
4. Bake for 30 minutes or until the edges just begin to brown.  Allow to cool for at least two hours to give the bars a chance to set, then remove from the pan and cut into squares with a large, sharp knife.