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These peanut butter marshmallow squares are a nostalgic, no-bake treat—the perfect blend of creamy, chewy, and sweet. With a soft, chewy texture, a hint of butterscotch, and brightly colored marshmallows, they come together in under 20 minutes. I’ll show you exactly how to avoid the common pitfalls that make these bars too sticky, too hard, or too gooey. My pro tip: always cool the peanut butter mixture before folding in the marshmallows, and freeze your marshmallows for the best results.

Why This Recipe Works

This recipe relies on the magic of melted butterscotch chips and peanut butter, which bind the marshmallows into a soft, chewy matrix. The key to the right texture is the ratio of fats (butter and peanut butter) to sugar (butterscotch chips), which creates a stable, creamy base. Too much butter makes the squares greasy; too little makes them dry. The butterscotch chips add a subtle caramel note, while the peanut butter brings depth and protein, helping the squares hold together. The mini marshmallows add a pillowy chew and a pop of color. Proper cooling ensures the marshmallows retain their shape and don’t melt into a gluey mess.

Ingredients

• Unsalted butter, 113g (½ cup)
  Purpose: Provides richness and helps the mixture bind together.
• Creamy peanut butter, 250g (1 cup)
  Purpose: Adds flavor and structure. Use a brand with a smooth texture (not natural or oily).
• Butterscotch chips, 300g (1.5 cups)
  Purpose: Sweetness and a chewy, caramel-like texture.
• Mini marshmallows, 250g (4–5 cups, rainbow recommended)
  Purpose: Adds chewiness and visual appeal.
• Vanilla extract, 5ml (1 tsp)
  Purpose: Enhances flavor and balances sweetness.

Equipment

• 20x20cm (8×8-inch) baking pan
• Parchment paper
• Medium saucepan
• Wooden spoon or silicone spatula
• Measuring cups and spoons
• Kitchen scale (recommended for accuracy)
• Optional: Offset spatula for leveling

Step-by-Step Instructions

Step 1: Prepare the Pan
Line the 20x20cm pan with parchment paper, letting it overhang the sides for easy removal. Set aside.

Step 2: Freeze the Marshmallows
Place the bag of mini marshmallows in the freezer for 15–20 minutes. This prevents them from melting too fast when folded in.

Step 3: Melt Butter, Peanut Butter, and Butterscotch Chips
In a medium saucepan over low heat, combine the butter, peanut butter, and butterscotch chips. Stir frequently until completely melted and smooth—about 5–7 minutes. Do not let the mixture boil or overheat.
Visual cue: The mixture should be glossy and stir easily, with no graininess.

Step 4: Cool the Mixture
Remove the pan from heat. Let it cool for 10–15 minutes, stirring occasionally.
Visual cue: The pan should feel cool enough to touch on the bottom, not hot.

Step 5: Fold in Marshmallows and Vanilla
Add the frozen marshmallows and vanilla extract. Gently fold using a spatula until all marshmallows are coated.
Visual cue: Marshmallows should be mostly whole, not melted. The mixture will be thick and sticky.

Step 6: Spread and Chill
Pour the mixture into the prepared pan. Spread evenly with the spatula, pressing gently to level the surface. Do not pack tightly.
Refrigerate for at least 1 hour until firm.

Step 7: Slice and Serve
Using the parchment “handles,” lift the slab out. Cut into squares with a sharp knife.
Visual cue (correct): The squares should hold their shape and reveal colorful marshmallows throughout.

Troubleshooting: Common Failures and Fixes

• Problem: Squares are too sticky/gooey
  Likely causes: Peanut butter mixture was too hot, or marshmallows were not cooled enough.
  Fix: Ensure the mixture has cooled before adding marshmallows; always freeze marshmallows.
• Problem: Squares are too hard or crumbly
  Likely causes: Overheated mixture, too much butterscotch, or undermixed marshmallows.
  Fix: Heat gently, don’t boil, and fold in marshmallows quickly.
• Problem: Squares fall apart easily
  Likely causes: Too little butter or too much peanut butter.
  Fix: Use the exact ratios, and use a high-quality creamy peanut butter.
• Problem: Squares look dry
  Likely causes: Mixture was overheated or cooled too long.
  Fix: Stir frequently and remove from heat as soon as melted.

Substitutions and Variations

• Dairy-free: Use vegan butter and dairy-free chocolate chips.
• Gluten-free: Use gluten-free marshmallows (check label).
• Nut-free: Replace peanut butter with sunflower seed butter.
• Flavor swaps: Add a pinch of salt, swap butterscotch for chocolate chips, or stir in chopped nuts after folding marshmallows.

Storage, Make-Ahead, and Freezing

• Counter: Store in an airtight container for up to 3 days.
• Fridge: Keep for up to 1 week. Bring to room temp before serving.
• Freezer: Wrap well and freeze for 1–2 months. Thaw at room temperature.
• Do not freeze: After slicing—freezing before cutting gives neater squares.

Serving Suggestions

Serve as a snack, dessert, or party treat. Pair with a glass of milk or a scoop of vanilla ice cream for contrast. These squares are rich, so a small square is plenty.

FAQs

1. Can I use regular marshmallows?
   Yes, but use about 1/3 fewer and cut them into quarters for best distribution.
2. How to prevent my squares from melting?
   Cool the mixture before adding marshmallows, and freeze them first.
3. Can I make these gluten-free or dairy-free?
   Yes—see variations above. Use gluten-free and dairy-free marshmallows.
4. How to double the recipe?
   Use a 23x33cm (9×13-inch) pan and double all ingredients.
5. Best type of peanut butter?
   Use a commercial creamy peanut butter with no added oil or sugar.
6. Can I bake these in an air fryer or OTG?
   No—these are no-bake. They are meant to set in the fridge.

Notes from My Kitchen (Testing Log)

• Batch 1: Marshmallows melted completely. Lesson: cool mixture before adding marshmallows; freeze marshmallows.
• Batch 2: Mixture was too thick. Adjustment: less butterscotch, more butter.
• Batch 3: Final success—perfect chewiness and marshmallow retention.
  Chosen method: Cool mixture, add frozen marshmallows, fold quickly.

Nutrition and Disclaimer

Approximate per serving (1 square):

• Calories: 220
• Fat: 12g
• Sugar: 20g
  Values are estimates; adjust for brands and portion size. Follow food-safety best practices.

Final Thoughts

These peanut butter marshmallow squares are a crowd-pleaser that’s easy to make and hard to mess up—if you follow the key steps. The balance of flavors and textures is what makes them memorable. With a little practice, you’ll get the perfect chewy, colorful squares every time. Store them right, and they’ll stay delicious for days.

No-Bake Peanut Butter Marshmallow Squares: Chewy, Colorful & Foolproof

Course: DessertCuisine: AmericanDifficulty: Easy

Servings

4

servings

Prep time

15

minutes

Cooking timeminutes

Calories

240

kcal

Total time

1

hour 

15

minutes

These no-bake peanut butter marshmallow squares are a nostalgic treat with a soft, chewy texture and a hint of butterscotch. Colorful mini marshmallows add a fun pop, making them perfect for parties, snacks, or gifting. Easy to make and even better chilled or frozen.

Ingredients

• Unsalted butter, 113g (½ cup)

• Creamy peanut butter, 250g (1 cup)

• Butterscotch chips, 300g (1.5 cups)

• Mini marshmallows, 250g (4–5 cups, rainbow recommended)

• Vanilla extract, 5ml (1 tsp)

Directions

• Prepare the Pan:
  Line the 20x20cm pan with parchment paper, letting it overhang the sides for easy removal. Set aside.
• Freeze the Marshmallows:
  Place the mini marshmallows in the freezer for 15–20 minutes.
• Melt Butter, Peanut Butter, and Butterscotch Chips:
  In a medium saucepan over low heat, combine the butter, peanut butter, and butterscotch chips. Stir frequently until completely melted and smooth (5–7 minutes). Do not let the mixture boil.
• Cool the Mixture:
  Remove from heat and let cool for 10–15 minutes, stirring occasionally.
• Fold in Marshmallows and Vanilla:
  Add the frozen marshmallows and vanilla extract. Gently fold using a spatula until all marshmallows are coated.
• Spread and Chill:
  Pour the mixture into the prepared pan. Spread evenly with the spatula. Refrigerate for at least 1 hour until firm.
• Slice and Serve:
  Lift the slab out using the parchment “handles.” Cut into squares with a sharp knife.

Notes

• Storage
  Counter: Store in an airtight container for up to 3 days.
  Fridge: Keep for up to 1 week. Bring to room temperature before serving.
  Freezer: Wrap well and freeze for 1–2 months. Thaw at room temperature.
• Notes
  For best results, use a creamy peanut butter with no added oil or sugar.
  Freeze marshmallows before folding to prevent melting.
  These squares are best served cold or frozen for a chewy texture.