Instructions
Preheat your oven to 375 degrees Fahrenheit. Line the 13×9-inch pan with parchment paper, leaving a 2-inch overhang on the sides.
Cover the bottom of the pan with a layer of graham crackers, breaking them into sections as needed to fit properly.
In the bowl of an electric mixer with the paddle attachment, cream together the room-temperature butter, granulated sugar, and light brown sugar until smooth and fluffy.
Add the eggs and vanilla extract to the mixture. Mix until well combined, making sure to scrape down the sides of the bowl.
In a separate large bowl, whisk together the all-purpose flour, salt, and baking soda.
Gradually add the flour mixture, chocolate chips, and mini marshmallows to the butter mixture. Mix until the ingredients are just combined, taking care not to overmix the dough.
Evenly distribute the cookie dough on top of the graham crackers in the prepared pan, pressing it down flat. If desired, top with additional mini marshmallows for an extra gooey touch.
Bake the bars at 375˚F for 25-30 minutes or until they turn golden brown and a toothpick inserted into the center comes out clean. If the cookie dough browns faster than the center bakes, cover the pan with foil during the baking process.
Once out of the oven, immediately place the Hershey’s Milk Chocolate Bar pieces on top of the warm bars. The residual heat will gently melt the chocolate, adding an irresistible creaminess to the bars.
Allow the bars to cool for 20-30 minutes before lifting them out of the pan. This cooling period will help the chocolate set slightly, making it easier to cut and serve. Please note that the chocolate bars may remain soft and melty at room temperature, adding to the lusciousness of these treats.
