These Ooey Gooey S’mores Bars are oozing with melted milk chocolate, marshmallow fluff, and optional Biscoff cookie butter; sandwiched between two layers of a soft and chewy cookie crust. Everyone’s favorite summer snack now comes in dessert bar form!

General
Why you'll love these
Ingredient notes
Visual walk-through
Get the recipe
Frequently Asked Questions
Tips for layering
How to cut these bars
How to store
Nutrition information
Ingredients

If I could eat one dessert for the rest of my life, it might just have to be these s’mores bars. But don’t take my word for it, they’re so good that my four year old requested these for his birthday “cake” last year and has requested them AGAIN for his birthday next month. Yeah. They’re just that good.

Why you’ll love these

Ridiculously easy. If you’re a fan of s’mores, but don’t love the roasting outside part, then these bars are for you!
Unbelievably gooey. I mean. Just look at the photos! Sticky marshmallow fluff, oozing melted chocolate, creamy cookie butter all sandwiched between soft cookie bars…drool.
Customizable. Swap the milk chocolate for dark for a more “sophisticated take” or use peanut butter or pistachio butter instead of the cookie butter for another fun twist!
Perfect for parties. Trust me. Bring these to your next gathering (4th of July summer cook-out, Christmas party, doesn’t matter) and I promise you, you’ll be everyone’s favorite.

Ingredient notes

Cookie Crust

Butter – salted or unsalted butter are fine. The recipe was tested using unsalted butter. If using salted, reduce the additional salt in half.
Sugars: Granulated Sugar and Dark Brown Sugar – in a pinch, you can use all granulated sugar or all dark brown sugar if that’s what you have on hand, but using a combination of both will give you the best flavor and texture. Light brown sugar may be used to replace the dark brown sugar.
Egg – be sure you’re using 1 large egg; they come in all different sizes.
Vanilla Extract – or vanilla bean paste. Omit if you don’t have any on hand, it won’t make or break the recipe.
Baking Powder – not baking soda. Baking soda needs an acid (like buttermilk or lemon juice) to activate it.
Flour – use all-purpose flour for the best texture. I don’t recommend using another flour.
Salt – table salt was used in the original recipe. Other salt such as kosher salt may be used, but it’s not as “salty”, so you may need to use more.
Biscoff Cookies – you may know these as the Delta airline cookies. These are crushed into the dough for added flavor and texture. Graham crackers may also be used, but I think biscoff cookies are better, because they’re crunchier and more flavorful!

Filling

Biscoff Cookies – kept whole for added crunch. These may be omitted in the filling if you don’t want a crunchy texture. Graham crackers may also be used instead.
Hershey’s Milk Chocolate Bars – you’ll need 2 (4.4. oz) bars. These are classic for a s’mores, but play around with different brands or varieties of chocolates such as dark chocolate, cookies and cream chocolate, caramel chocolate, etc.
Cookie Butter – aka Biscoff or speculoos butter. If you don’t know what it is, it’s a spread similar to peanut butter, but it’s made from crushed speculoos cookies and tastes like a combination of cinnamon, brown sugar, and caramel. Peanut butter may also be used, but I like that cookie butter is nut-free for gatherings!
Marshmallow Fluff – or creme! You’ll need 1 (7 oz) jar. This will give you the goo-iest texture, but mini marshmallows may be used in a pinch. I’m guessing you’d need about 1/2 of a 16 oz bag.

Visual walk-through

Crush some of the Biscoff cookies (or graham crackers) into a fine crumb.
Make the base of the cookie dough.
Stir in the cookie crumbs.
Press half the mixture into the bottom of a prepared 8×8 baking dish.
Top with milk chocolate bars.
Optional: spread on a layer of cookie butter (or peanut butter).
Optional: top with Biscoff cookies (or graham crackers).
Spread on marshmallow fluff.
Scoop remaining dough into dough balls.
Flatten each piece.
Gently lay a piece on top of the marshmallow fluff.
Repeat with remaining flattened cookie dough balls to create a top crust.
Bake until golden brown.

Tips for layering

LIghtly grease your hands or spatula. The dough and marshmallow fluff are thick and sticky. Lightly grease your hands or spatula before pressing the bottom crust into the pan or smoothing out the marshmallow fluff so they spread evenly without pulling up the parchment paper or other layers.
Press the bottom layer firmly to the corners. Press the dough all the way into the corners and make sure the thickness is even to create a sturdy base for the other toppings.
Don’t spread marshmallow fluff like frosting. Dollop spoonfuls all over the surface, then use the greased spatula to gently smooth it out as best as you can.
Flatten the top dough pieces before adding. Then lay them over the filling like patchwork to create the top crust.
Use a light hand with the top layer. Pressing down too firmly can cause the fillings to squish out.

How to cut these bars

For very gooey-licious bars, allow to cool completely to room temperature (about 4 hours), then slice (or scoop) and serve.

For cleaner slices, cool to room temperature, then cover and chill in the fridge overnight before slicing and serving!

Pro tip

If you’re not sharing, feel free to scoop directly out of the pan after cooling for a few minutes for a deliciously messy treat!

How to store

Leftovers will last in a sealed airtight container in the fridge for 1 week or in the freezer for 2-3 months.

These can be eaten chilled, room temperature, or my favorite: warmed up in the microwave after slicing.

– Jennifer

Ooey Gooey S’mores Bars