1 cup butter, softened
2 cups granulated sugar
4 large eggs
2 teaspoons vanilla extract
5 cups all-purpose flour
1 teaspoon salt
1/2 teaspoon baking soda
5 1/2 graham cracker sheets
1 (10-ounce bag) white chocolate chips
2 cups mini marshmallows
Preheat oven to 350 degrees. Line a 9x9-inch baking dish with foil, making sure the foil extends over the sides and spray with a non-stick baking spray; set aside.
In the bowl of an electric mixer, cream butter and sugar together until light and fluffy, about 2 minutes. Add eggs, one a time, mixing well after each addition. Stir in the vanilla.
In a medium bowl, whisk together the flour, salt, and baking soda.
With the mixer on low, slowly add the flour mixture to the butter mixture, mixing until just combined.
Divide cookie dough in half. Press half of the dough into the bottom of the baking dish. Layer graham crackers side-by-side on top of the cookie dough. Sprinkle with marshmallows and white chocolate chips. Top with the remaining cookie dough, pressing down gently.
Bake for 20-25 minutes, or until a toothpick inserted into the cookie bars tests clean. Remove from oven and allow to cool completely. When cooled, use the foil to lift bars from the pan, cut into squares, and serve.