Preheat oven to 350 degrees. Line an 8-inch square baking pan with parchment paper and spray with nonstick cooking spray.

In a large bowl, using a mixer, add the butter and both sugars and beat until light and fluffy, 2-3 minutes.

Add in egg and vanilla and mix until combined.

In another medium bowl, combine the flour, graham cracker crumbs, baking powder and salt.

Add the dry ingredients to the wet ingredients and mix just until combined.

Press half the dough into the prepared pan and bake for 15 minutes.

Remove from the oven but keep the oven on. Layer the chocolate bars on top of the pan and then sprinkle with marshmallows.

Sprinkle the remaining cookie dough on top of the marshmallows, it’s ok if you have marshmallow exposed to let the marshmallow peek through, it looks cool!

Bake for 15 minutes or until just lightly browned and the bars look set. Allow the bars to cool down in the pan before cutting them. I took a butane lighter torch and slightly charred some of the marshmallow, but it’s not necessary, I just did it for that real s’more charred effect. Also, you can add chocolate bar sections on top of the bars if desired.

When you cut the bars, they can still be slightly warm, or cooled completely. I like to take a sharp knife and spray it with non-stick spray to help the marshmallow from sticking to the knife, it works really well.