S’mores Cake Mix Cookie Bars
You will love this recipe for S’mores Cake Mix Cookie Bars if you want something fast, pretty, and impossible to mess up. These are the kind of dessert bars you can throw together after work, bring to a last minute get together, or bake for a cozy movie night when you are craving smores but have zero interest in fussing with a campfire. With one bowl, a box of cake mix, and classic s’mores ingredients, you get gooey, chocolatey bars that taste like a summer bonfire in under an hour.
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Ingredients for S’mores Cake Mix Cookie Bars
- 1 (15.25 ounce) box yellow cake mix
- 2 large eggs
- 1/2 cup (1 stick) unsalted butter, melted
- 3/4 cup semisweet chocolate chips
- 4 to 5 full graham cracker sheets, divided
- 1 1/2 to 2 cups mini marshmallows
- 2 (1.55 ounce) Hershey’s milk chocolate bars, divided
How to Make S’mores Cake Mix Cookie Bars
1. Prepare the pan and oven
Preheat the oven to 350°F. Line a 9×9-inch baking pan with parchment paper, leaving some overhang for lifting out the bars.
2. Prepare the graham crackers and chocolate
Break the graham crackers into bite-sized pieces. Chop one Hershey’s bar into smaller pieces and set it aside for the topping. Leave the second chocolate bar whole for the final step.
3. Make the cookie dough
Add the yellow cake mix, eggs, and melted butter to a large mixing bowl. Stir until completely combined and a thick cookie dough forms.
4. Add the mix-ins
Fold the semisweet chocolate chips and about 3 graham cracker sheets’ worth of pieces into the dough. Reserve the remaining graham cracker pieces for the topping.
5. Press and bake
Press the dough evenly into the prepared pan, making sure it reaches the corners. Bake for 20–24 minutes, until the edges are lightly golden and the center looks almost completely set.
6. Add the toppings
Remove the pan from the oven, but leave the oven on. Sprinkle the mini marshmallows, chopped Hershey’s chocolate, and remaining graham cracker pieces over the warm cookie base.
7. Finish baking
Return the pan to the oven for 3–5 minutes, until the marshmallows are soft and puffy and the chocolate begins to melt.
8. Toast the marshmallows
If desired, switch the oven to broil. Broil for about 20–30 seconds, watching constantly, until the marshmallows are lightly toasted.
9. Add the reserved chocolate
Break the remaining Hershey’s bar into individual rectangles. While the bars are still warm, gently press the rectangles into the topping. The residual heat will soften the chocolate and help it stick.
10. Cool and cut
Let the bars cool in the pan until firm enough to lift. Transfer the slab to a cutting board using the parchment overhang and allow it to finish cooling before cutting into 9 large squares or 12 smaller bars.
Pro Tips
- Line the pan well. Parchment with overhang is your best friend; it keeps the bars from sticking and makes lifting and cutting much cleaner.
- Do not overbake the base. Let the cookie base bake until the center is set and a toothpick comes out without wet batter before adding the s’mores topping. The bars will return to the oven for only a few minutes, so the base can be almost fully baked at this point. This also makes it easier to test the center without digging through the marshmallows and chocolate, and helps prevent the toppings from burning before the bars are done.
- Watch the broiler like a hawk. If you toast the marshmallows, keep the oven door cracked and your eyes on the pan. Move it out the second they hit your favorite golden color.
- Let them cool before slicing. I know they smell amazing, but cutting too early can turn everything into a gooey slide. Give them at least 20 to 30 minutes so the chocolate can set up a bit.
- Adjust the marshmallows to your taste. Use closer to 1 1/2 cups if you want more cookie showing, or the full 2 cups if you like extra gooey smores cookies style bars.
- Make ahead friendly. These bars keep well covered at room temperature for about 2 days. For longer storage, refrigerate and bring to room temp before serving.
- Easy variation ideas. Swap semisweet chips for milk or dark chocolate chips. Use a chocolate cake mix for a twist on classic s’mores dessert bars. Add a sprinkle of flaky sea salt on top after baking for a sweet and salty vibe.
FAQs
Can I use a different flavor of cake mix?
Yes. Chocolate, white, vanilla, or butter golden cake mix should work with the same measurements and instructions. Butter golden cake mix is especially good for creating a rich, buttery cookie base, while chocolate makes a richer, double-chocolate s’mores bar. Yellow cake mix gives these bars their classic flavor and appearance.
Do I have to use a 9×9 pan?
A 9×9-inch pan works best and creates thick, chewy cookie bars. You can use an 8×8-inch pan, but the bars will be thicker and may need a few extra minutes of baking time. I don’t recommend using a 9×13-inch pan for a single batch because the cookie layer will be too thin. If using a different pan, watch for the visual signs of doneness rather than relying only on the baking time.
How do I keep the chocolate rectangles on top from melting completely?
Add them after you turn off the oven and remove the pan. Press them in gently, not too deep, so they soften but still hold their shape as the bars cool.
Do these freeze well?
These cookie bars are best enjoyed fresh. Although you can freeze them, the toasted marshmallows may become sticky or rubbery after thawing, and the graham crackers can lose their crunch. For the best taste and texture, store the bars at room temperature and enjoy them within a few days.
Can I double the recipe for a crowd?
Yes; double everything and bake in a 9×13 pan. The bars will be slightly thicker, so add a few extra minutes to the initial baking time and keep an eye on the edges.
I love these S’mores Cake Mix Cookie Bars because they give you that nostalgic campfire flavor without any hassle. One box of cake mix plus a few pantry staples turns into gooey, golden dessert bars that look impressive on a platter but are easy enough for a busy weeknight. If you are looking for cake mix desserts that always get compliments, these smores cookies inspired bars deserve a spot in your regular rotation.
S'mores Cake Mix Cookie Bars
Ingredients
- 1 box yellow cake mix 15.25 ounces
- 2 eggs
- 1/2 cup (1 stick) unsalted butter melted
- 3/4 cup semisweet chocolate chips
- 4 to 5 full graham cracker sheets divided
- 1 1/2 - 2 cups mini marshmallows
- 2 Hershey’s milk chocolate bars divided
Instructions
- Preheat the oven to 350°F. Line a 9×9-inch baking pan with parchment paper, leaving some overhang for lifting out the bars.
- Break the graham crackers into bite-sized pieces. Chop one Hershey’s bar into smaller pieces and set it aside for the topping. Leave the second chocolate bar whole for the final step.
- Add the yellow cake mix, eggs, and melted butter to a large mixing bowl. Stir until completely combined and a thick cookie dough forms.
- Fold the semisweet chocolate chips and about 3 graham cracker sheets’ worth of pieces into the dough. Reserve the remaining graham cracker pieces for the topping.
- Press the dough evenly into the prepared pan, making sure it reaches the corners. Bake for 20–24 minutes, until the edges are lightly golden and the center looks almost completely set.
- Remove the pan from the oven, but leave the oven on. Sprinkle the mini marshmallows, chopped Hershey’s chocolate, and remaining graham cracker pieces over the warm cookie base.
- Return the pan to the oven for 3–5 minutes, until the marshmallows are soft and puffy and the chocolate begins to melt.
- If desired, switch the oven to broil. Broil for about 20–30 seconds, watching constantly, until the marshmallows are lightly toasted.
- Break the remaining Hershey’s bar into individual rectangles. While the bars are still warm, gently press the rectangles into the topping. The residual heat will soften the chocolate and help it stick.
- Let the bars cool in the pan until firm enough to lift. Transfer the slab to a cutting board using the parchment overhang and allow it to finish cooling before cutting into 9 large squares or 12 smaller bars.
