Step 1

Preheat oven to 375° F. Spray an 8x8 inch pan with nonstick spray and line with parchment paper.

Step 2

In a medium bowl, combine flour, graham cracker crumbs, baking soda, and salt. Whisk together and set aside.

Step 3

Beat butters and sugars in a large bowl until fluffy. Add egg and vanilla and beat well. Gradually stir in flour mixture until just combined, and fold in chocolate chips by hand.

Step 4

Press the dough into the prepared pan and top with miniature marshmallows in an even layer.

Step 5

Bake for 25-30 minutes or until a toothpick inserted in the center comes out clean. Turn oven to broil and cook for about 5 more minutes until the marshmallows are toasted on top.

Step 6

When cookie bars are cool enough to handle, remove from pan using the parchment paper and cut into 12 equal pieces.