Thick and Chewy S'mores Cookie Bars

Ooooo, these are good! I posted this picture on Facebook and have had some requests for the recipe, so here it is! I took my Thick and Chewy M&M Cookie Bars recipe, which is by far my most viewed (over 325k!), and tweaked it. Added a graham crust, and substituted marshmallows, and chocolate chips. Love them, especially the gooey marshmallow! To get fine and uniform graham cracker crumbs, just give them a whirl in the blender. Still easy to make, with no mixer required! I even mailed some to my sister in WI, in a 2 day priority mail box, and they arrived in perfect shape. Scroll down to the very bottom for an easier version without the crust. They are calling your name!

Thick and Chewy S'Mores Cookie Bars
1 1/2 cups graham cracker crumbs (9 or 10 long crackers)
4 TBSPs butter, melted
2 1/8 cups flour
1/2 tsp salt
1/2 tsp baking soda
12 TBSPs butter, melted and cooled slightly
1 cup brown sugar
1/2 cup white sugar
1 large egg
1 large egg yolk
2 tsps vanilla extract
2 cups marshmallows, divided
1 1/2 cups chocolate chips, divided

1. Preheat the oven to 325 degrees. Adjust the oven rack to lower-middle position. Line a 9X13-inch baking pan with foil, letting the excess hang over the edges of the pan by about 1 inch so you can grab those edges and pull the bars from the pan after they have baked. Spray the foil-lined pan with nonstick cooking spray.
2. Combine crushed graham crackers and 4 TBSPs melted butter in medium sized bowl. Stir with fork to combine. Pour graham mixture into prepared pan covering the bottom of the pan and press down firmly with hands. Refrigerate until needed.
3. Mix the flour, salt, and baking soda together in medium bowl; set aside. Whisk the melted butter and sugars in a large bowl until combined. Add the egg, egg yolk, and vanilla and mix well. Using a rubber spatula, fold the dry ingredients into the egg mixture until just combined; do not overmix. Fold in 1 cup of marshmallows and 1 cup of chocolate chips.
4. Carefully spoon batter into the prepared pan placing dollops all around the prepared crust. Smooth the top with the spatula with a pressing motion. Sprinkle remaining marshmallows and chocolate chips on top and press in slightly.
5. Bake until the top of the bars is light golden brown, slightly firm to the touch, and edges start pulling away from sides of pan, 24-28 minutes. Cool on a wire rack to room temperature. Remove the bars from the pan by lifting the foil overhang and transfer them to a cutting board. Cut into squares and serve.

Easier version: Don't make the crust. Chop 4 graham crackers into pieces. You don't need the extra 4 TBSPs of butter. Follow the directions for the cookies bars, adding the chopped pieces to the cookie batter with the marshmallows and choc chips.