These peanut butter marshmallow squares, also known as confetti squares or butterscotch marshmallow squares, are the best nostalgic childhood treat! Creamy peanut butter is mixed with melted butterscotch chips and mini marshmallows for a super easy no bake dessert.
What's your favorite childhood treat? I'm torn between puppy chow and these peanut butter marshmallow confetti squares. They're gooey, chewy, fluffy little squares that are sweet, a little salty, and totally delicious.
With a flavor similar to scotcharoos, confetti squares are hard to resist! The best part is that they only take 5 minutes to make. All your have to do is melt the butter, peanut butter, and butterscotch, mix in your rainbow marshmallows, and let the bars set.
These are the perfect retro, no-bake treat for the holidays, summertime, or for any occasion. Or you can just make them on a weekend to share with your kids or to relive your childhood.
Here are some notes about the ingredients used. For quantities and the full instructions, see the recipe card below.
- Butterscotch chips- Butterscotch chips are flavored with brown sugar and butter. You can find them at most grocery stores in the baking section near the chocolate chips.
- Peanut butter- Like in these brown butter peanut butter cookies, you can use crunchy or creamy peanut butter depending on your preference. I'm on team Creamy PB because it makes the butterscotch fudge extra luscious. Make sure to use salted peanut butter.
- Butter- High quality butter, like Kerrygold, will make your confetti squares taste even better. If you're using unsalted peanut butter, use salted butter and vice versa.
- Mini marshmallows- Peanut butter marshmallow squares are usually made with rainbow mini marshmallows. These are usually fruit flavored. If you're not a fan of fruity marshmallows, feel free to use regular mini marshmallows.
- Vanilla extract- A splash of vanilla rounds out the flavor profile and enhances the other ingredients.
- Butterscotch chips: There's another version of butterscotch squares that's made with chocolate! Substitute the butterscotch chips for chocolate chips for this flavor variation.
- Peanut butter: If you want to experiment with different flavors, try substituting the peanut butter for another nut butter, like almond butter, Sunbutter, or cashew butter.
Helpful Equipment and Tools
- Melt the peanut butter and butterscotch in a large saucepan- a kitchen staple! I recommend buying one that's higher quality with a heavy bottom. It'll last for years and will prevent the things you make in it from getting scorched.
- You'll need an 8x8" or 9x9" square baking pan. You can also use a 9x5" loaf pan but the squares will be much thicker. Make sure to line the pan with parchment paper so the bars don't stick and lift out easily.
Step by Step Instructions
Before you start, place your bag of marshmallows in the freezer. Line your square baking pan with parchment paper and set aside.
STEP 1: First, add the butterscotch chips, peanut butter, and butter to a large pot or saucepan over medium-low heat.
STEP 2: Next, stir the ingredients together as they melt until they're smooth, creamy, and completely melted. This will take about 5 minutes.
STEP 3: Next, take the pot off the stove and mix in the vanilla and marshmallows quickly. Chilling the marshmallows before hand keeps them from melting in the hot peanut butter.
STEP 4: Pour the mixture into your lined pan, spreading it evenly across. Cover the pan in plastic wrap and place it in the refrigerator for at least 1 hour to chill and harden.
Once they set, slice the squares with a sharp knife and serve.
Expert Baking Tips
- Don't overheat the peanut butter. If the peanut butter/butterscotch mixture gets too hot, the sugars in the butterscotch chips will crystalize. This will result in grainy bars instead of soft and creamy ones.
- Freeze the marshmallows. Throw the bag of marshmallows into the freezer for a few minutes while you heat the peanut butter. The marshmallows are less likely to melt if they're chilled.
- Use a sharp knife. When you're ready to cut and serve the butterscotch squares, use the sharpest knife you have! Run it under hot water, slice, wipe off any peanut butter and repeat for the cleanest cuts.
Additions and Variations
If you're looking to add some extra flavor and texture to your butterscotch squares, here are a few suggestions:
- Chocolate: Stir in some chocolate chips or melt some chocolate and drizzle it over the top of the squares.
- Pretzels: Chop some pretzels and mix them in with the marshmallows. The salty and crunchy pretzels create a nice contrast to the soft sweetness of the marshmallows.
- Caramel: Swirl caramel sauce into the peanut butter mixture before adding the marshmallows for extra richness and gooeyness.
- Nutella: Warm up some Nutella and drizzle it over the squares.
- Chopped peanuts: Sprinkle some chopped peanuts on top of the squares for extra crunch and texture.
Storage and Freezing
Store the peanut butter marshmallow squares in an airtight container in the refrigerator for up to 5 days. You can let them sit on the counter for 30 minutes before eating to reach room temperature or enjoy them cold.
Wrap leftover squares in plastic wrap and place them in a freezer-safe bag. Freeze for up to 2 months. Let them soften in the refrigerator or on the counter for about an hour before eating. They're actually super refreshing and delicious eaten frozen too!
Frequently Asked Questions
They are! Check your ingredients to make sure each is certified gluten free and not cross-contaminated before you make these for someone following a gluten free diet.
If your confetti squares are grainy and crumbly instead of smooth and creamy, it's because the peanut butter, butter, and butterscotch mixture got too hot and the sugars crystalized. Make sure to heat everything slowly to prevent this.
More Bars to Try
Peanut Butter Marshmallow Squares (Confetti Squares)
- 1 saucepan
- 1 square baking pan 8x8" or 9x9"
- Line a square baking pan with parchment paper and set aside.
- Add the butterscotch chips, peanut butter, and butter to a large pot or saucepan over medium-low heat.310 grams butterscotch chips, 250 grams peanut butter, 57 grams butter
- Stir the mixture constantly until it is completely melted and smooth.
- Take the pot off the heat and fold in the marshmallows and vanilla quickly.280 grams rainbow mini marshmallows, 1 teaspoon vanilla extract
- Pour the mixture into the prepared pan. Spread with a rubber spatula or the back of a spoon into an even layer.
- Refrigerate for about 1 hour or until they're slightly hardened and set.
- Remove from the pan, slice into squares, and enjoy!