Soft & Chewy Fluffernutter Bars Recipe – Gooey Marshmallow Peanut Butter Dessert

If you love the classic fluffernutter sandwich or crave a sweet-and-salty treat, these Fluffernutter Bars are your new go-to dessert. Soft and chewy peanut butter bars are layered with gooey marshmallow fluff in the middle, then topped with additional peanut butter dough for a decadent twist. Perfect for bake sales, family gatherings, or an indulgent treat at home, these bars combine the comforting flavors of peanut butter and marshmallow in a way that’s nostalgic and irresistible. With a buttery, chewy base, sweet marshmallow center, and slightly crispy edges, each bar is packed with flavor and texture. These bars are easy enough for home bakers and make a visually impressive dessert that’s fun to serve for any occasion.

Why You’ll Love This Recipe

• Soft & Chewy: Perfectly balanced texture, with a moist peanut butter base.
• Gooey Marshmallow Center: Melty, sweet, and indulgent.
• Layered Flavor: Sweet, salty, and nutty all in one bite.
• Family-Friendly: Loved by kids and adults alike, a nostalgic favorite.
• Beginner-Friendly: Straightforward steps that produce impressive results.
• Make-Ahead Friendly: Bars store well at room temperature and retain texture.

Ingredients Breakdown

Bars

• 2 1/4 cups all-purpose flour
• 1 teaspoon baking powder
• 1/4 teaspoon salt
• 3/4 cup unsalted butter, softened
• 3/4 cup brown sugar
• 1/3 cup white sugar
• 1 1/2 cups smooth peanut butter*
• 1 large egg
• 1 large egg yolk (in addition to the egg; discard the white)
• 7 oz jar marshmallow fluff

Yield: 15 bars

Ingredient Notes:

• Peanut Butter: Adds richness and moisture; use smooth peanut butter with stabilizers for best results.
• Marshmallow Fluff: Creates a gooey, sweet layer in the center.
• Butter & Sugars: Combine to make a soft, chewy base with slightly crisp edges.
• Flour, Baking Powder & Salt: Provide structure and balance the sweetness.

Tools & Equipment Needed

• 9 x 13-inch baking pan
• Parchment paper or aluminum foil
• Medium mixing bowl
• Large mixing bowl
• Electric mixer or whisk
• Spatula or wooden spoon
• Oven
• Sharp knife (greased optionally with non-stick spray)

Optional Helpful Tools:

• Offset spatula for spreading marshmallow fluff
• Silicone spatula for pressing dough

Step-by-Step Instructions

1. Preheat Oven & Prepare Pan: Preheat oven to 350°F. Place the oven rack in the middle. Line a 9 x 13-inch pan with parchment paper, leaving an overhang, or use aluminum foil and lightly grease.
2. Mix Dry Ingredients: In a medium bowl, whisk together 2 1/4 cups all-purpose flour, 1 teaspoon baking powder, and 1/4 teaspoon salt. Set aside.
3. Combine Butter & Sugars: In a large bowl, beat 3/4 cup softened butter, 3/4 cup brown sugar, and 1/3 cup white sugar until soft and fluffy.
4. Add Peanut Butter & Eggs: Beat in 1 1/2 cups smooth peanut butter, followed by 1 large egg and 1 large egg yolk, until smooth.
5. Add Dry Ingredients: With mixer on low, gradually add the flour mixture to the peanut butter mixture, about half at a time, mixing gently to combine.
6. Reserve 1 Cup of Batter: Remove about 1 cup of batter from the bowl for later topping.
7. Form Base Layer: Press the remaining peanut butter dough evenly into the bottom of the prepared pan.
8. Bake Base Layer: Bake in the preheated oven for 25 minutes, or until the top appears fully set.
9. Add Marshmallow Fluff: Remove pan from oven. Carefully spread the entire 7 oz jar of marshmallow fluff on top of the baked peanut butter layer.
10. Top With Reserved Dough: Pinch small pieces (~1 inch each) of the reserved peanut butter dough. Flatten slightly and place on top of the marshmallow layer, covering about 80–90% of the surface.
11. Bake Again: Return pan to oven and bake for 10 minutes, or until the top peanut butter layer is set.
12. Cool Bars: Allow bars to cool at room temperature for at least 1 hour before slicing.
13. Slice & Serve: Lift bars using the parchment paper or foil overhang. Use a thin, sharp knife (optionally greased) to slice 15 bars.

Tips & Variations

• Peanut Butter Options: Do not use natural peanut butter without stabilizers; it may separate. For crunchy peanut butter, use 1 3/4 cups.
• Pan Type: Metal pans yield slightly crispier edges; glass pans give softer edges.
• Storage: Keep in an airtight container at room temperature for up to 5 days.
• Gluten-Free Option: Substitute with a 1:1 gluten-free flour blend.
• Chocolate Variation: Add chocolate chips on top of the marshmallow layer before placing reserved dough pieces.

Flavor Profile

Fluffernutter Bars offer a perfect combination of soft, chewy peanut butter base and gooey marshmallow center, with a slight crisp on the top edges. The peanut butter adds richness and a nutty flavor, while the marshmallow contributes sweetness and creamy mouthfeel. Each bite delivers a nostalgic, indulgent taste reminiscent of a classic fluffernutter sandwich but in bar form.

Nutritional Overview (Per Serving)

Nutrient	Amount
Calories	410 kcal
Protein	9 g
Carbs	46 g
Fat	23 g
Saturated Fat	9 g
Cholesterol	49 mg
Sodium	167 mg
Potassium	236 mg
Fiber	2 g
Sugar	26 g
Vitamin A	318 IU
Calcium	41 mg
Iron	2 mg

Dietary Notes: Vegetarian-friendly; contains gluten, dairy, and peanuts.

Make-Ahead & Meal Prep Tips

• Prep Early: Dough can be mixed ahead; bake just before serving for best texture.
• Storage: Keep cooled bars in an airtight container at room temperature for up to 5 days.
• Freezing: Not recommended due to marshmallow layer, which may change texture.
• Serving Tip: Slice with a thin, greased knife to prevent sticking and maintain clean edges.

Frequently Asked Questions

1. Can I use natural peanut butter?
Not recommended; may separate and affect texture.

2. Can I make these bars in a smaller pan?
Yes, but baking time may need adjustment; check the base layer carefully.

3. Can I use chocolate marshmallow fluff?
Yes, for a chocolate variation, though the flavor will be sweeter.

4. Can I add nuts?
Yes, sprinkle chopped peanuts on top of marshmallow before adding dough.

5. How can I make edges less crispy?
Use a glass pan for slightly softer edges.

Cooking Timeline

Task	Time
Prep Time	30 min
Cook Time	35 min
Total Time	1 hr 5 min
Servings	15 bars

Serving Suggestions

• Serve warm or at room temperature.
• Plate with a garnish of chopped peanuts for visual appeal.
• Great for dessert tables, parties, or gifting.
• Pair with coffee or milk for a cozy treat.

Recipe Variations

1. Chocolate Fluffernutter Bars: Add chocolate chips under marshmallow layer.
2. Nutty Bars: Sprinkle chopped peanuts or walnuts before topping with reserved dough.
3. Mini Fluffernutter Bites: Bake in mini muffin tins for individual servings.
4. Salted Peanut Butter: Sprinkle flaky sea salt on top for contrast with sweet marshmallow.

Ingredient Spotlight

• Peanut Butter: Adds moisture, nutty richness, and structure. Smooth is recommended.
• Marshmallow Fluff: Central to gooey texture and sweet flavor, creating the signature fluffernutter effect.

Pro Baking Tips

• Reserve dough for top layer to prevent marshmallow from spreading too thin.
• Avoid overmixing flour to maintain a chewy texture.
• Use parchment paper or foil overhang for easy removal and slicing.
• Cool bars completely before slicing to ensure layers hold.

Storage & Freezing Guide

• Room Temperature: Store in airtight container up to 5 days.
• Freezing: Not recommended due to marshmallow layer; freezing may alter texture.
• Reheating: Serve at room temperature; warming may cause marshmallow to become overly sticky.

Nutrition Estimate Table (Per Serving)

Nutrient	Amount
Calories	410 kcal
Protein	9 g
Carbs	46 g
Fat	23 g
Fiber	2 g

Dietary Notes: Vegetarian-friendly; contains gluten, dairy, and peanuts.

Expanded Conclusion

These Fluffernutter Bars are a nostalgic, indulgent dessert perfect for peanut butter and marshmallow lovers. Soft, chewy, and layered with gooey marshmallow, they bring a playful twist to the classic sandwich. Easy to make yet impressive to serve, they’re perfect for parties, family desserts, or a special sweet treat. Save this recipe, share it with friends, and enjoy every bite of these decadent, fun bars.

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