Chewy oat cookie base layered with marshmallow creme and dotted with chocolate chips—like s’mores meets oatmeal bar, all baked in one square pan.

Why You Will Love This Recipe

• Combines the best parts of cookie and s’mores in bar form.

• A rich marshmallow center with chocolate chips gives gooey, melty contrast.

• Oatmeal adds heartiness and chew.

• Easy to slice and serve, great for potlucks or dessert trays.

• Store well and travel nicely.

Oatmeal Cookie S’mores Bars

Oatmeal Cookie S’mores Bars are a delightful mashup of cookie, s’mores, and bar dessert. You start with a soft, buttery oat cookie dough that’s lightly sweet and wholesome thanks to quick oats. The dough is pressed in half into a foil‑lined square pan to form a bottom crust. Then comes the indulgent middle layer of marshmallow creme—warmed just slightly so it spreads easily, but still thick enough to hold its own. That layer captures the essence of classic s’mores (only without broiling). On top of that, you scatter chocolate chips so every bite has bursts of melting chocolate.

The trick is preserving the gooey quality of the marshmallow layer while ensuring the top cookie dough layer bakes through without burning. So you spoon or scoop remaining dough, pressing it gently over the marshmallow layer to create a patchwork cover—some crust showing, some dough overlapping—rather than a full seal. As the bars bake at 350°F, the top layer browns gently, edges become crisp, and the middle remains soft and slightly jiggly until cooled. Once cooled, the bars firm enough to slice but remain gooey within.

When you bite into these bars, you taste buttery oat cookie, sweet marshmallow, and chocolate all at once. The contrast in textures—soft, chewy, melty—is part of the appeal. Plus, they’re made in one pan, easy to transport, and perfect for dessert lovers who want something more creative than a standard cookie.

Servings

9–12 bars (depending on size)

Time

Ingredients

• ½ cup unsalted butter, softened

• 1 cup packed brown sugar

• 1 egg

• 1 teaspoon vanilla extract

• ½ teaspoon baking soda

• ½ teaspoon salt

• 1¼ cups all‑purpose flour

• 1½ cups quick‑cooking oats

• 1 (7 oz) jar marshmallow creme

• 1 cup chocolate chips (milk or semi‑sweet)

Instructions

1. Preheat oven to 350°F. Line a 9×9″ square pan with foil and spray with nonstick spray.

2. Cream butter and brown sugar until smooth.

3. Beat in egg, vanilla, baking soda, and salt.

4. Mix in flour, then slowly incorporate oats.

5. Press half the dough into bottom of prepared pan (oiling your hands helps with stickiness).

6. Microwave marshmallow creme 10–20 sec until soft and spreadable. Spread over bottom dough, leaving a narrow border at edges.

7. Sprinkle chocolate chips over marshmallow layer.

8. Scoop remaining dough and flatten pieces to cover top, filling gaps.

9. Bake 23–28 minutes until top is golden and firm around edges (center may jiggle).

10. Cool completely before slicing (the middle will be gooey when warm).

11. Store in airtight container up to 4 days.

Tips

• Spray your fingers or spoons when handling sticky dough.

• Don’t overbake—the goal is a slight jiggle in center.

• Cool thoroughly so the bars firm up before slicing.

• Use quality chocolate chips for better melt.

• Line pan with foil so you can lift bars out cleanly.