Preheat the oven to 350F and grease and line an 8×8 baking pan with parchment paper, allowing the paper to hang over the sides for easy release later.

In a medium bowl, whisk together the ground graham crackers, flour, baking powder, and salt. Set aside.

In a large mixing bowl using a wooden spoon or electric mixer, mix together the room temperature butter, brown sugar, and sugar.

When it’s smooth, well combined and lightened in color, thoroughly mix in the egg and vanilla.

Dump in the dry ingredients and stir to combine. Before the flour is fully incorporated, toss in the chocolate chips and work them into the dough.

The dough will be rather thick at this point, so feel free to use your hand to knead the chips in! Just be careful not to over work the dough.

Press ⅔ of the dough into the bottom of the baking pan.

Place an even layer of the chocolate bars on top, arranging them to completely cover the cookie dough. Cut the bars as needed to fit the entire surface.

Now for the peanut butter, mix with the flour and salt and spread over the chocolate bars.

Then arrange a layer of graham crackers on top of the peanut butter. Same as the chocolate bars, completely cover the surface and cut the graham crackers as needed.

Now plop most of the marshmallow fluff on top, leaving about ¼ cup in the jar. For easy spreading, lightly spray your tool with some nonstick stray and spread the fluff in an even layer.

Crumble the remaining cookie dough on top, covering most of the surface with some small pockets of marshmallow peaking through.

Bake the bars for 20-25 minutes. They’re ready when the fluff is puffing through the surface and the cookie dough looks lightly golden around the edges.

Allow the bars to cool at room temperature for 30 minutes, then transfer to the refrigerator to chill for at least 1 hour and 30 minutes. It’s important for the bars to set before slicing, otherwise they can fall apart.

When the bottom of the pan is no longer warm to the touch, lift the bars out of the pan and slice. Enjoy!