Go Back
+ servings
A close-up shot of a single layered brownie bar, highlighting the fudgy brownie texture and the melted marshmallow center.
FL Recipes

Marshmallow Peanut Butter Brownie Bars (The Ultimate Fudgy Treat)

Discover the ultimate fudgy treat with these Marshmallow Peanut Butter Brownie Bars. This easy recipe features a rich brownie base, a gooey marshmallow center, and a creamy peanut butter topping for a truly decadent dessert experience.
Prep Time 15 minutes
Cook Time 28 minutes
Total Time 43 minutes
Servings: 16 bars
Course: Dessert
Cuisine: American
Calories: 250

Ingredients
  

For the Fudgy Brownie Layer
  • 1/2 cup unsalted butter melted
  • 1 cup granulated sugar
  • 2 large eggs
  • 1 tsp vanilla extract
  • 1/2 cup all-purpose flour
  • 1/3 cup unsweetened cocoa powder
  • 1/4 tsp salt
For the Gooey Marshmallow Center
  • 2 cups miniature marshmallows
For the Rich Peanut Butter Topping
  • 3/4 cup creamy peanut butter
  • 1/4 cup powdered sugar
  • 2 tbsp unsalted butter melted

Equipment

  • 1 8x8 inch baking pan
  • 2 Mixing Bowls
  • Parchment Paper

Method
 

  1. Preheat your oven to 350°F (175°C). Grease an 8x8 inch baking pan and line it with parchment paper, leaving an overhang on the sides to use as handles later.
  2. In a large bowl, whisk together the melted butter and granulated sugar until well combined. Beat in the eggs one at a time, followed by the vanilla extract.
  3. In a separate bowl, whisk together the all-purpose flour, cocoa powder, and salt. Gradually add the dry ingredients to the wet ingredients, mixing until just combined. Be careful not to overmix.
  4. Pour the batter into your prepared pan and spread it into an even layer. Bake for 20-25 minutes, or until a toothpick inserted into the center comes out with moist crumbs attached.
  5. Remove the brownies from the oven and immediately sprinkle the miniature marshmallows evenly over the hot surface.
  6. Place the pan back in the oven for 2-3 minutes, just until the marshmallows get puffy and slightly melted.
  7. While the marshmallows are melting, quickly mix the creamy peanut butter, powdered sugar, and melted butter in a small bowl until smooth.
  8. Remove the pan from the oven. Drop spoonfuls of the peanut butter mixture over the melted marshmallows. Using an offset spatula, gently spread the peanut butter over the marshmallow layer.
  9. Let the bars cool completely in the pan on a wire rack, for at least 4 hours, or until set. For best results and cleaner cuts, you can chill them in the refrigerator for an hour before slicing.

Nutrition

Calories: 250kcalProtein: 4gFat: 14gFiber: 2g

Notes

Pro Tip: For perfectly clean slices, chill the bars in the refrigerator for at least one hour before cutting.
Storage: Store in an airtight container at room temperature for up to 3 days.
Keyword fudgy brownies,layered brownies,marshmallow peanut butter brownies

Tried this recipe?

Let us know how it was!
Pin Recipe