S’mores Cookie Bars take the campfire favorite and turn it into something you can slice, stack, and pass around without needing a fire pit or a stick. A soft cookie dough base gets layered with graham crackers, chocolate bars, and marshmallows, then topped with more dough and baked until gooey in the middle and golden on top. The whole pan comes together in under an hour, including a short cooling period before slicing.
This recipe works well among family dinner desserts, since it cuts into neat squares that hold up better than a fully melted s’mores square eaten straight off a stick. It also counts as one of those sharable desserts perfect for a table full of people who want a little bit of chocolate and marshmallow without too much mess.
S’mores Cookie Bars Ingredients
- 2 1/4 cups all purpose flour
- 1 tsp baking soda
- 1/2 tsp salt
- 1 cup unsalted butter, softened
- 3/4 cup granulated sugar
- 3/4 cup brown sugar
- 2 large eggs
- 2 tsp vanilla extract
- 6 whole graham crackers
- 2 standard chocolate bars, broken into pieces
- 2 cups mini marshmallows
Building the Cookie Bar Layers
Press about two thirds of the cookie dough evenly into the bottom of the pan first, since an uneven base bakes unevenly too, leaving some spots doughy and others dry. Wetting your fingers slightly while pressing helps keep the dough from sticking to your hands as much.
Lay the graham crackers over the dough in a single layer, breaking pieces as needed to fill any gaps, then top with the chocolate and marshmallows before adding the remaining dough. Flattening small chunks of the remaining dough into thin pieces rather than one solid layer makes it easier to cover the marshmallows without pressing them out to the edges.
How to Make S’mores Cookie Bars
- Preheat oven to 350°F and line a 9×13 pan with parchment paper.
- Whisk together flour, baking soda, and salt in a bowl.
- Beat butter, granulated sugar, and brown sugar until light and fluffy.
- Add eggs one at a time, then mix in vanilla extract.
- Gradually add the dry ingredients, mixing just until combined.
- Press about two thirds of the dough into the bottom of the pan.
- Layer graham crackers, chocolate pieces, and marshmallows on top.
- Flatten the remaining dough into thin pieces and cover the marshmallows.
- Bake for 25 to 30 minutes until the top is golden brown.
- Cool completely in the pan before slicing into squares.
Pro Tips for Clean Slices
Let the bars cool almost completely before slicing, since warm marshmallow pulls apart in long strings rather than cutting cleanly. A wait of about an hour on the counter makes the difference between neat squares and a sticky mess on the knife.
Run the knife under hot water and wipe it dry between cuts, especially through the melted chocolate layer, since this small habit keeps each smores square looking sharp instead of smeared. A serrated knife also tends to glide through the layers more smoothly than a straight-edge blade.
Ingredient Substitutions and Variations
Dark chocolate or peanut butter cups can replace the standard chocolate bars for a different flavor twist, while chocolate graham crackers swap in nicely for regular ones if that is what is on hand. Both changes keep this recipe flexible enough to fit different dessert ideas simple enough for a weeknight bake.
Full-size marshmallows cut into quarters work in place of minis if that is all the pantry has, though minis melt a bit more evenly across the pan. For a s’mores bake dessert with a bit more crunch, a light sprinkle of crushed graham crackers over the top layer of dough before baking adds extra texture.
Fixing Common Baking Issues
If the top layer looks pale while the bottom seems overdone, the oven rack was likely positioned too low. Move the pan to the middle rack next time, and rotate it halfway through baking if the oven tends to run hot on one side.
Bars that fall apart when sliced usually just need a longer cooling time before cutting. Chilling the pan in the refrigerator for 20 minutes after it cools on the counter firms everything up enough for clean, sturdy squares.
Storing and Serving This Sweet Dessert
Store sliced bars in an airtight container at room temperature for up to 3 days, or in the refrigerator for up to a week if the kitchen runs warm. A quick 10 second warm-up in the microwave brings back a bit of that gooey marshmallow texture for anyone eating leftovers.
These bars travel well, making them a solid pick among birthday party dessert ideas or even silent auction dessert ideas where a sturdy, pre-sliced treat holds up better than something delicate. Wrap individually in parchment for easy grab and go servings at a gathering.
FAQ
Can I make these bars ahead of time?
Yes, they can be baked a day ahead and stored covered at room temperature, which also gives the layers time to firm up nicely.
Why did my marshmallow layer disappear during baking?
This usually happens when the top dough layer is too thin or has gaps, letting marshmallow bubble up and spread. Cover it fully with slightly thicker pieces of dough.
Can I freeze S’mores Cookie Bars?
Yes, wrap individual squares tightly and freeze for up to 2 months. Thaw at room temperature for about an hour before serving.
Do I need to chill the dough before baking?
No chilling is needed here, since pressing the dough directly into the pan works well without the spreading issues a drop cookie might have.
What size pan works best for this recipe?
A standard 9×13 inch pan gives the right thickness for even baking, though a smaller pan works too with a slightly longer bake time.
S’mores Cookie Bars
Ingredients
Equipment
Method
- Cream butter and sugars, then add eggs and vanilla.
- Mix in dry ingredients until just combined.
- Press two thirds of the dough into a lined pan.
- Layer graham crackers, chocolate, and marshmallows on top.
- Cover with remaining dough and bake at 350°F for 25 to 30 minutes.
- Cool completely before slicing into squares.
Notes
- Cool nearly completely before slicing for clean squares.
- Wipe the knife between cuts for neater edges.
- Freezes well for up to 2 months.
- Great for parties and potlucks since it slices and travels easily.
