The pastel no-bake squarePeanut butter · butterscotch · rainbow marshmallows
Fiona Dowling · May 2017 · four ingredients
Confetti Squares
Fiona Dowling’s confetti squares fold rainbow mini marshmallows through a smooth peanut butter–butterscotch base, then chill into 16 soft, bright slices.
This licensed ingredient study shows the pastel palette behind the confetti effect; the finished squares use miniature rainbow marshmallows held in a peanut butter–butterscotch base.Photo by Tiia Monto / Wikimedia Commons · CC BY-SA 3.0
Makes
16 squares
Ingredients
4
Active
15 min
Chill
1–2 hr
The whole square is a temperature trick. Butter, peanut butter, and butterscotch must become warm enough to flow as one, then cool enough to receive marshmallows without erasing their edges. There is no oven and almost no technique beyond knowing when to stop heating and when to start folding.
Fiona Dowling’s four-ingredient formula leaves that decision visible. Four cups of marshmallows make a fudgier candy with a generous amber matrix; five cups turn the same base into a lighter mosaic. Either way, a cold slab and a wiped knife reveal the reason these Canadian potluck squares earned their name: every piece carries a different arrangement of color.
“Confetti squares are a super easy, no bake retro recipe. Also known as peanut butter marshmallow squares or butterscotch marshmallow squares—these bars are soft, chewy, peanut buttery and deliciously sweet.”
Weigh the chips
The source’s “one bag” means 300 grams. Package sizes change; the weight keeps the original formula intact.
Keep the flame low
Butter, peanut butter, and chips need only enough heat to become smooth. A simmer is already too much.
Cool before color
The base should stay fluid but lose its heat before the marshmallows enter, or the confetti dissolves into streaks.
Press with restraint
Ease the mixture into the corners without crushing the soft pockets that make every cut surface different.
The candy equationLoosen · bind · set · scatter
Four ingredients, each holding a different part of the square
Nothing is ornamental. The base needs its measured fat, peanut body, and 300 grams of chips before the marshmallows can stay suspended as confetti.
01
Unsalted butter
A quarter-cup loosens the peanut butter and helps the butterscotch chips melt into a continuous, sliceable coating.
Cut it into pieces so the pan turns smooth before any one area overheats.02
Peanut butter
One cup gives the base its savory edge, creamy body, and enough structure to hold marshmallow pockets after chilling.
A conventional homogenized jar is predictable here; separated natural peanut butter may set softer.03
Butterscotch chips
Three hundred grams provide the sweetness and amber candy structure that firm the melted base in the refrigerator.
Read the scale, not the front of the bag. Modern packages do not always match the source weight.04
Rainbow mini marshmallows
Four to five cups turn one dense candy base into a soft mosaic with visible pastel pockets at every slice.
Use 4 cups for fudgier bars or 5 for a lighter, more confetti-forward bite.
Amber + pastelThe base and the bright pockets
Peanut butter softens the candy; butterscotch makes it hold
One full cup of peanut butter gives the melted base body and a salty counterweight. A conventional homogenized jar is the most predictable choice for a clean set.Photo by Dr Stephen Dann / Wikimedia Commons · CC BY-SA 2.0
One bag is a weight
The 2017 formula names 300 grams. Measure that number even when today’s package is smaller.
These are hard butterscotch candies, not the baking chips used in the recipe; their amber color is the visual cue for the square’s sweet, buttery base.Photo by Evan-Amos / Wikimedia Commons · CC BY-SA 3.0
The no-bake clockLine · melt · cool · fold · set · slice
Fifteen active minutes build the slab; cold time draws the grid
Low heat makes the base smooth. The refrigerator does the structural work, and a sharp knife finishes sixteen deliberate squares.
0:00
Line the pan
Make a greased foil or parchment sling in an 8-inch square pan; use 9 inches for a thinner slab.
+2
Load the saucepan
Add butter, peanut butter, and exactly 300 grams of butterscotch chips before turning on low heat.
+5
Stir to gloss
Scrape the bottom and corners for about 3–5 minutes, stopping as soon as no chip outline remains.
+8
Cool the base
Move the pan off heat. Stir once or twice and wait until the base is fluid but no longer hot to the touch below.
+12
Fold the confetti
Gently coat 4–5 cups marshmallows, working promptly without compressing or smearing them.
+15
Level, then chill
Ease the mixture into the corners, level lightly, and refrigerate until the slab is firm enough to lift.
1:15+
Cut sixteen
Lift out by the sling, divide into a four-by-four grid, and wipe the sharp blade between cuts.
From saucepan to sliceGlossy · cooled · distinct · gentle · clean
Five readings protect the gloss and keep the confetti visible
The timer is secondary. The useful cues are a bubble-free base, a comfortable pan, intact marshmallows, and a chilled slab that lifts without bowing.
01
Glossy, never bubbling
The base flows from the spatula in a thick ribbon with no chip shapes, scorched specks, or simmering edge.
02
Fluid but not hot
The saucepan can be handled comfortably from beneath while the mixture still moves when stirred.
03
Distinct pastel pockets
Marshmallows stay plump and separate rather than shrinking into colored trails through the base.
04
Closed gaps, soft pressure
The top is level enough to slice but individual marshmallows still look rounded instead of ironed flat.
05
A clean chilled grid
The slab lifts as one piece and the knife reveals tidy amber edges around visible pink, yellow, green, and white centers.
The tray planMeasure early · set cold · separate layers
Chill as one slab, then cut only when the edges are firm
Confetti squares are built for advance work. Keep air and warmth away after cutting, and the soft mosaic stays tidy for the dessert tray.
Before melting
Line the pan and measure every ingredient first. Once the base is smooth, the useful window is short.
For a gathering
Make the slab a day ahead, cover in the pan, then cut it cold shortly before arranging the tray.
For five days
Keep squares airtight in the refrigerator with parchment between layers so the cut surfaces stay clean.
For two months
Freeze airtight with parchment separators, then thaw overnight in the refrigerator before serving.
Confetti Squares
Fiona Dowling’s 16-square peanut butter–butterscotch mosaic with 4–5 cups of rainbow mini marshmallows.
Line an 8-inch square pan with foil or parchment, leaving enough overhang to lift out the slab. Lightly grease the lining. A 9-inch square pan also works and makes slightly thinner squares.
Put the butter, peanut butter, and 300 grams butterscotch chips in a medium heavy-bottomed saucepan. Set it over low heat and stir often, scraping the bottom and corners, until the mixture is completely melted and smooth, about 3–5 minutes. Do not let it simmer or boil.
Take the saucepan off the heat and set it on a rack or trivet. Let the mixture cool to room temperature, stirring once or twice so the edges do not set ahead of the center. It should remain fluid but no longer feel hot through the base of the pan.
Choose 4 cups marshmallows for a softer, fudgier square or 5 cups for a lighter square with more distinct confetti pockets. Fold them through the cooled peanut butter mixture gently and promptly until every piece is coated without being crushed.
Scrape the mixture into the prepared pan. Ease it into the corners and level the top with the spatula; press only enough to close large gaps, not hard enough to flatten the marshmallows.
Refrigerate until firm, about 1–2 hours. Lift out by the lining, peel the foil or parchment from the sides, and cut into 16 squares with a sharp knife. Wipe the blade between cuts for clean edges.
Source and research references: the queued legacy path and live My Recipe Magic card for legacy ID 2502223555, Fiona Dowling attribution, May 25, 2017 date, 16-square yield, complete ingredient transcription, original description, and nutrition panel; Fiona’s maintained Just So Tasty Confetti Squares for the full method, 8- or 9-inch pan, low heat, room-temperature cooling, 4-versus-5-cup texture choice, 1–2-hour chill, five-day refrigeration, and two-month freezing; the Delish Test Kitchen confetti-square method for independent agreement that the melted base must cool before marshmallows enter and that refrigeration sets the slab; and Land O’Lakes butterscotch peanut bars for independent confirmation of low heat, constant stirring, a 3–5-minute melt, brief cooling, and refrigerated storage for the same butter–peanut butter–butterscotch system. The source quantities and identity remain unchanged; added details clarify package drift, saucepan cues, gentle packing, clean cutting, storage, allergens, and nutrition uncertainty.
