Peanut Butter Marshmallow Squares are my go to fix for those days when you want something sweet but you do not want to bake, chill for hours, or dirty every bowl you own. You know that moment when people are coming over, the kids are hovering in the kitchen, and you suddenly remember you promised a treat? Yep, this is that recipe. These squares are soft, chewy, and just a little sticky in the best way. The peanut butter flavor comes through strong, but the marshmallows keep it playful and light. If you can stir and press a mixture into a pan, you can make these. 
How To Make Peanut Butter Marshmallow Bars
I have made these Peanut Butter Marshmallow Squares so many times that I can basically do it on autopilot, but I still get excited every single time I cut that first row. The smell alone is worth it. Here is the simple flow.
The Story Behind This Recipe
Hey, I’m Cuts Food! This Peanut Butter Marshmallow Squares was built for busy nights: simple steps, reliable results, and flavor that makes people ask for seconds. Peanut Butter Marshmallow Squares are my go to fix for those days when you want something sweet but you do not want to bake, chill for…
Quick step by step (no stress)
- Prep your pan: Line an 8×8 pan with parchment paper or lightly grease it. Parchment makes lifting out the whole slab way easier.
- Melt the base: In a medium pot on low heat, melt butter and butterscotch chips together. Stir often so nothing scorches.
- Add peanut butter: Once smooth, stir in peanut butter until the mixture looks glossy and uniform.
- Fold in marshmallows: Turn off the heat, let it cool for a minute, then gently fold in mini marshmallows. You want them coated, not fully melted into soup.
- Press and chill: Press into the pan with lightly buttered hands or a greased spatula. Chill until set, then slice.
That is really it. The only tricky part is not eating it straight from the pot. I usually chill mine for about 45 to 60 minutes. If you are in a rush, pop the pan in the freezer for 15 minutes, then move it to the fridge so the texture stays nice and chewy.
Little tip from my own mistakes: keep the heat low the whole time. Butterscotch chips can seize or scorch if you blast them. Low and slow is the calm path.
If you are in a peanut butter mood (same), you might also like my quick sweet snack obsession, irresistible dark chocolate peanut butter bark. It has that same low effort, big reward energy.
Simple Ingredients You Need For The Peanut Butter Marshmallow Squares Recipe
I love recipes that do not ask for a scavenger hunt. This Peanut Butter Marshmallow Squares recipe is basically a pantry win. You can keep most of this stuff on hand and be ready for surprise bake sales, movie nights, or that random Tuesday when you need a treat.
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What you need
- Butter: salted or unsalted both work. Salted gives a little extra balance.
- Butterscotch chips: this is where the cozy sweetness comes from.
- Peanut butter: creamy is classic, but we will talk crunchy later.
- Mini marshmallows: mini works best because they mix in evenly.
That is the core. If you want to get extra, you can add a pinch of salt or a tiny splash of vanilla, but honestly it is not required. The simplicity is part of why Peanut Butter Marshmallow Squares are such a repeat recipe in my house.
Also, ingredient quality actually matters here because there are so few. Use a peanut butter you really like the taste of. I usually go with a standard creamy peanut butter, not the super natural kind that separates, because it sets more reliably.
And if you are into super simple peanut butter treats, you might want to bookmark this one too: 2 ingredient peanut butter fudge. It is dangerously easy.
How To Customize Marshmallow Butterscotch Bars
Once you make these once, it is hard not to start daydreaming about variations. Think of these as marshmallow butterscotch bars with a peanut butter backbone. You can tweak them based on what is in your pantry or who you are making them for.
Here are my favorite ways to switch it up without breaking the recipe:
Add crunch: Stir in chopped pretzels, peanuts, or crispy rice cereal. If you love that sweet salty vibe, you would probably also be into butter toffee pretzels for snacking alongside these bars.
Chocolate drizzle: Melt a little chocolate and drizzle over the top after chilling. Let it set before slicing, unless you enjoy messy fingers (no judgment).
Extra butterscotch: Sprinkle a few butterscotch chips on top right after pressing into the pan. They look cute and you get little pops of flavor.
Holiday style: Toss in festive sprinkles for birthdays or holidays. This is a fun move when kids are involved because they feel like they helped.
“I brought these to a family game night and everyone kept sneaking back for another square. My brother literally asked if I could make a double batch next time. They are sweet, but not too sweet, and the marshmallows make them so soft.”
One thing I do not recommend: adding too many extras at once. If you overload the mix, the bars can crumble or not set as well. Pick one or two fun add ins and call it good.
If you want another easy peanut butter dessert with that same crowd pleasing vibe, check out this peanut butter cup dump cake. It is cozy and basically makes itself.
Can I Use Crunchy Peanut Butter Instead Of Smooth In These No Bake Peanut Butter Marshmallow Squares?
Yes, you totally can. Crunchy peanut butter works great in no bake Peanut Butter Marshmallow Squares if you want more texture. The little peanut bits add a nice bite and make the squares feel a tiny bit less sticky.
Here is what to know before you swap:
Texture changes: crunchy makes the bars slightly more structured, which some people love.
Mixing: it takes a bit more stirring to get everything smooth before the marshmallows go in, but it is not hard.
Brand matters: if your crunchy peanut butter is very oily or separates a lot, your bars might set softer. If that is what you have, just chill them a little longer.
I have done half creamy and half crunchy too, especially when I am trying to please both camps. In my house, there is always someone with an opinion about creamy versus crunchy, and somehow it becomes a whole debate.
If you are a cookie person and peanut butter is your love language, you might also like these cake mix peanut butter cookies. They are fluffy, fast, and very weeknight friendly.
Can I Freeze These Peanut Butter Marshmallow Bars?
Yes, and I do it all the time. Freezing Peanut Butter Marshmallow Squares is a great trick if you want to make them ahead or if you just want to keep a secret stash for emergencies. I call it dessert insurance.
Here is the best way to freeze them so they still taste good later:
Freeze as a slab first: Let the bars set in the fridge, then freeze the whole pan for about 30 minutes so it firms up.
Slice and wrap: Cut into squares. Wrap each square in plastic wrap, then place them in a freezer bag or airtight container.
Label it: Date it. They will keep well for about 1 to 2 months.
Thaw gently: Let a square thaw at room temp for 20 to 30 minutes. If you eat it half frozen, it is actually pretty amazing and kind of chewy like nougat.
One small note: marshmallows can get a little firmer after freezing, but once they warm up they go back to that soft bite. If you are taking them to a party, thaw them before you go so they are at their best.
Common Questions
Do Peanut Butter Marshmallow Squares need to be refrigerated?
I recommend it, especially if your kitchen is warm. The fridge helps them set cleanly and keeps them from getting too sticky.
Why did my butterscotch mixture get grainy?
Usually it is from heat that is too high. Next time, keep the burner on low and stir constantly. Once butterscotch chips scorch, the texture will not fully recover.
Can I use big marshmallows instead of mini?
You can, but it is annoying. You will need to cut them into smaller pieces so they mix in evenly. Mini marshmallows are just easier and give better texture.
How do I cut them without making a mess?
Chill them first, then use a sharp knife. Wipe the knife between cuts, or lightly grease the blade. It makes the slices cleaner.
What is the best way to serve them for a party?
Cut them small, like bite size. They are rich, so smaller pieces disappear fast and people can grab one without committing to a huge square.
A sweet little wrap up (and a couple helpful references)
If you need a fast treat that makes people happy, Peanut Butter Marshmallow Squares are the answer. You melt, stir, fold, press, and chill, and suddenly you have a pan of chewy, peanut buttery goodness. Keep the heat low, use a peanut butter you like, and do not be afraid to play with add ins once you have the basic version down. If you want to compare other takes, I found both Peanut Butter Marshmallow Squares (4 Ingredients!) – Gluesticks Blog and Peanut Butter Marshmallow Squares – Culinary Cool super handy for extra tips. Now go make a batch, hide a few squares for yourself, and let me know if you team creamy or team crunchy.
Peanut Butter Marshmallow Squares
Ingredients
Method
- Line an 8×8 pan with parchment paper or lightly grease it.
- In a medium pot on low heat, melt butter and butterscotch chips together, stirring often.
- Once smooth, stir in peanut butter until glossy and uniform.
- Turn off the heat, let cool for a minute, then gently fold in mini marshmallows.
- Press mixture into the pan with buttered hands or a greased spatula.
- Chill until set (about 45-60 minutes), then slice into squares.
