Step 1: Preheat your oven to 350°F and lightly grease your pan. A cast iron muffin pan works great for individual servings, but you can also use a traditional 9x13 baking dish for classic brownie squares.

Step 2: Prepare your brownie mix according to the package directions. Bake until just about done—remove the pan from the oven with about 5 minutes left on the baking time. This ensures the brownies stay fudgy once you add the toppings.

Step 3: Layer graham crackers directly on top of the brownies while they’re still warm. Break larger pieces to fit as needed, creating a base for all that gooey goodness.

Step 4: Sprinkle mini marshmallows evenly over the graham crackers, followed by the chocolate bar pieces. Don’t be shy—extra chocolate always makes s’mores better!

Step 5: For that rustic, campfire-style look, crumble a few extra graham cracker pieces across the top. It adds texture and makes the dessert look extra inviting.

Step 6: Return the pan to the oven for 5 minutes, or just until the marshmallows start to puff up and turn golden brown. Keep an eye on them—marshmallows toast quickly!

Step 7: Allow your brownies to cool slightly before slicing. These are best served slightly warm when the marshmallows are soft, the chocolate is melty, and every bite tastes like campfire heaven.