Peanut Butter Mallow Bars

Category: Sweet Finishes & Fresh-Baked Joy

These peanut butter bars combine creamy peanut butter with gooey marshmallows and the crunch of chopped Nutter Butter cookies. Sweetened condensed milk is gently cooked with peanut butter and vanilla, then mixed with chips and marshmallows before being chilled to set. A sprinkling of salted peanuts on top adds a savory contrast to the richness, making each bite satisfying and textured. Chilling ensures firm bars that are easy to cut and enjoy as a sweet treat.

Breanna smiling at the camera.
Created By Breanna
Last updated on Mon, 10 Nov 2025 00:14:36 GMT
A close up of a peanut butter mallow bar. Save
A close up of a peanut butter mallow bar. | foodiffy.com

These peanut butter mallow bars are perfect for when you need a quick, indulgent treat that feels like a celebration in every bite. The combination of creamy peanut butter, sweet marshmallows, and crunchy Nutter Butter cookies makes this an easy go-to for dessert or snack time.

I first made this after wanting something sweet and nutty without turning on the oven on a summer day. It quickly became a crowd-pleaser during casual get-togethers.

Ingredients

  • Butter: softened for greasing to ensure easy removal and no sticking
  • Sweetened condensed milk: adds creamy sweetness as the dessert’s base choose well-sealed cans for freshness
  • Smooth peanut butter: for richness natural peanut butter may change texture so creamy store-bought works best
  • Peanut butter baking chips: melt smoothly and intensify that peanut flavor
  • Pure vanilla extract: enhances the sweetness and rounds the flavors
  • Nutter Butter cookies: add delightful crunch and peanut taste pick cookies that are fresh with no signs of staleness
  • Miniature marshmallows: bring that soft chewy contrast and a touch of sweetness that stays in pockets throughout
  • Chopped salted peanuts: add texture and a slight saltiness which balances the sugar nicely roasted and unsalted can be used to adjust salt

Instructions

Build The Prep:
Lightly butter an 8 by 8-inch pan focusing on the bottom and sides so the bars come out cleanly. This prevents sticking and helps with easy slicing later.
Melt Together Peanut Butter And Condensed Milk:
Place sweetened condensed milk and peanut butter in a heavy bottom saucepan over medium low heat. Stir constantly for 8 to 10 minutes until fully combined and starting to bubble gently. This slow heating lets the mixture thicken slightly and develop a rich flavor without burning.
Add Vanilla And Chips:
Remove the pan from heat and stir in the pure vanilla extract for flavor depth. Immediately add the peanut butter baking chips and stir until they melt completely creating a smooth creamy texture.
Mix In Cookies And Marshmallows:
Fold the chopped Nutter Butter cookies and miniature marshmallows into the mixture. Stir gently but thoroughly to spread out the crunch and sweetness. Do not overmix as some marshmallows should remain whole for texture.
Spread And Top:
Quickly pour and spread the mixture evenly into the prepared pan using a spatula. While still warm sprinkle the chopped salted peanuts evenly over the top so they stick as the bars cool.
Chill And Slice:
Place the pan in the refrigerator to chill for at least 2 hours or until set firmly. After chilling cut into squares of your preferred size. Store leftovers in an airtight container in the fridge to keep the bars firm and fresh.
A stack of peanut butter mallow bars.
A stack of peanut butter mallow bars. | foodiffy.com

My favorite ingredient has to be the Nutter Butter cookies. Their peanut taste and crunch lift the bars to another level. I remember making these bars every holiday and savoring how the marshmallows melted just enough while keeping their chew. It’s a comfort dessert that consistently brings smiles.

Storage Tips

Store bars in an airtight container in the refrigerator to keep them firm and fresh. They last for about a week chilled making them a handy ready treat. To soften before serving let them sit at room temperature for 10 minutes which brings out the gooey texture.

Ingredient Swaps

Peanut butter chips can be substituted with white chocolate or butterscotch chips if you want a different sweet note. Try almond butter instead of peanut butter for a milder nut flavor or sunflower seed butter if there are peanut allergies. Regular graham crackers can replace Nutter Butter cookies but the peanut flavor will be less pronounced.

Serving Ideas

Serve these bars with a scoop of vanilla ice cream for an extra decadent dessert. Cut into small bite-sized pieces and serve on a platter for parties and gatherings. Pair with a cold glass of milk or a cup of black coffee to balance the sweetness.

A stack of peanut butter mallow bars.
A stack of peanut butter mallow bars. | foodiffy.com

This recipe is a quick and fuss-free dessert perfect for any occasion. Enjoy the sweet and salty combination with ease.

Frequently Asked Recipe Questions

→ How do I prevent the peanut butter mixture from sticking while cooking?

Stir constantly over medium-low heat to prevent sticking and ensure the mixture heats evenly without burning.

→ Can I substitute the Nutter Butter cookies with other types?

Yes, other crunchy cookies like graham crackers or shortbread can work well for texture and flavor variation.

→ Why is chilling important before cutting the bars?

Chilling helps the mixture firm up, making the bars easier to cut and hold their shape when served.

→ What’s the purpose of salted peanuts on top?

Salted peanuts add a contrasting savory crunch that balances the sweetness and enhances overall texture.

→ How can I make cutting easier?

Line the pan with parchment paper before adding the mixture to help lift the bars out for cleaner slicing.

Peanut Butter Mallow Bars

Delicious peanut butter bars with marshmallows, cookie crunch, and salted peanuts for a perfect sweet snack.

Preparation Time
15 mins
Time to Cook
10 mins
Overall Time
25 mins
Created By: Breanna

Type of Recipe: Desserts & Baking

Cooking Difficulty: Suitable for Beginners

Cultural Origin: American

Portion Size: 16 Number of Servings (16 bars)

Dietary Options: Good for Vegetarians

Ingredients Required

→ Dairy and Fats

01 15 grams unsalted butter, softened
02 800 grams sweetened condensed milk (2 cans, 14 oz each)
03 180 grams creamy peanut butter

→ Flavourings

04 5 milliliters pure vanilla extract

→ Chocolate and Confectionery

05 280 grams peanut butter baking chips
06 200 grams miniature marshmallows

→ Cookies and Nuts

07 12 Nutter Butter cookies, chopped
08 60 grams salted peanuts, chopped

Guide to Cooking

Step 01

Lightly butter an 20x20 cm baking pan on the bottom and sides using softened butter. Set aside.

Step 02

In a heavy-bottomed large saucepan, combine sweetened condensed milk and peanut butter. Heat over medium-low, stirring constantly for 8 to 10 minutes until mixture is hot and bubbling gently, preventing sticking.

Step 03

Remove from heat. Stir in pure vanilla extract, then add peanut butter baking chips. Stir until fully melted and smooth.

Step 04

Fold in chopped Nutter Butter cookies and miniature marshmallows until evenly distributed, ensuring some marshmallows remain whole.

Step 05

Quickly spread the mixture evenly into the prepared pan. Sprinkle chopped salted peanuts over the top.

Step 06

Refrigerate for at least 2 hours or until set firmly. Cut into 16 portions and store in an airtight container under refrigeration.

Extra Suggestions

  1. Line the pan with parchment paper before adding the mixture to facilitate easier cutting.
  2. Adjust the quantity of marshmallows and peanuts according to personal preference.
  3. Keep bars refrigerated to maintain firmness and texture.

Necessary Equipment

  • 8x8 inch (20x20 cm) baking pan
  • Heavy-bottomed saucepan
  • Mixing spoon or spatula

Allergen Info

Always check ingredient labels for allergens, and talk to a health expert if you’re unsure.
  • Contains peanuts, dairy, and gluten (from cookies).

Nutritional Info (Per Serving)

Nutrition facts are for general information and shouldn’t replace professional health advice.
  • Energy (Calories): 350
  • Fats: 18 g
  • Carbohydrates: 45 g
  • Protein: 8 g