Preheat the oven to 325°F. Line an 8 x 8-inch baking pan with parchment paper.

In the bowl of a stand mixer fitted with the paddle attachment, add the butter, light brown sugar, and vanilla extract. Mix on low until combined and there are no chunks of butter.

Add the heavy whipping cream, flour, baking soda, and sea salt and mix together until a stiff cookie dough forms.

Place three-quarters of the dough (just eyeball it) into the baking pan and press it with your hands to form an even layer.

Top the cookie dough with the chocolate marshmallow crème and spread evenly.

Chop the chocolate bar into small chunks. Break the graham crackers into pieces and sprinkle the chocolate and graham crackers on top of the marshmallow.

Add the remaining cookie dough on top by breaking it into little chunks and adding evenly on top of the bars, allowing parts of marshmallow crème, chocolate, and graham crackers to show through.

Bake for 30 to 35 minutes or until the cookie portion looks lightly browned and it’s only a little jiggly. Allow to cool completely in the pan.

Cut the bars into 9 bars. Store in an airtight container for up to 5 days.