Crisped rice cereal
Any brand.
Also called Marshmallow Crispy Squares · राइस क्रिस्पी ट्रीट्स · رائس کرسپی ٹریٹس
Brown butter, extra marshmallows and a gentle hand make thick, chewy squares that stay soft for days.

Rice crispy treats are crisped rice cereal bound with melted marshmallow and butter, an American bake-sale classic since the 1940s. This homemade version adds brown butter and salt.
The main ingredients, with their English, Hindi and Urdu names.
Any brand.
Mini marshmallows melt fastest.

Unsalted.
Restaurant cooks do these things by habit. Here’s what each step is actually doing to the food, so you can cook by understanding instead of guesswork.
Melt the marshmallows over low heat, just until smooth.
Marshmallows are sugar, water and gelatin. Overheating drives off water and concentrates the sugar, which sets harder as it cools, so the treats turn tough.
Cook the butter until the milk solids turn golden brown.
The milk proteins and sugars in butter brown through the Maillard reaction, adding nutty, toffee-like flavor.
Press the mixture gently into the pan.
Pressing hard squeezes out the air between the cereal pieces and makes dense, hard bars.
Exact amounts and timings are in the recipe card below.
The marshmallows were cooked too hot or long, or the mixture was packed too firmly.
Fresh ones melt smoother; stale ones may need a splash of water.

Extra-gooey homemade rice crispy treats with brown butter and a pinch of salt. With the food science of why low heat keeps them soft instead of hard.