A classic rice krispie cake in a 9×13 pan needs 4 tablespoons of butter, 16 ounces of marshmallows and 8 cups of crisp rice cereal. Melt the butter and marshmallows over low heat, stir in the cereal, press it gently into a buttered 9×13 pan and let it set for an hour. The recipe makes 24 soft, thick bars.
The original three-ingredient recipe uses 10 ounces of marshmallows and 6 cups of cereal, which in a 9×13 pan gives thin, firm bars. The quantities here are scaled up for a thicker, softer, more marshmallowy cake that still cuts cleanly.
Why These Amounts for a 9×13 Pan
A 9×13 pan has about 117 square inches of base. Six cups of cereal spread over that makes bars about 3/4 inch thick; eight cups brings them to about 1 1/4 inches, which is what most people picture when they think of a bakery-style rice krispie cake. Raising the marshmallows in the same proportion (and adding a little extra) keeps the bars soft rather than dry.
Ingredients
- 4 tablespoons (57 g) unsalted butter, plus extra for the pan
- 16 ounces (450 g) mini marshmallows, divided
- 1 teaspoon vanilla extract
- 1/4 teaspoon salt
- 8 cups crisp rice cereal
Instructions
- Prepare the pan. Butter a 9×13 pan and a spatula, or line the pan with buttered parchment.
- Melt the butter. Melt the butter in a large pot over low heat. For a nutty flavour, keep cooking it for 3 to 4 minutes until it smells toasty and turns golden.
- Melt the marshmallows. Set aside 1 cup of marshmallows. Add the rest to the pot and stir over low heat until just melted and smooth. Take the pot off the heat and stir in the vanilla and salt.
- Add the cereal. Stir in the cereal and the reserved marshmallows until everything is evenly coated. The whole marshmallows give pockets of gooey marshmallow.
- Press lightly. Tip the mixture into the pan and press it into an even layer with the buttered spatula. Press gently; packing it hard is what makes rice krispie cakes tough.
- Set. Let the pan stand at room temperature for about 1 hour, then cut it into 24 bars.
Cook and Prep Times
- Prep: 10 minutes
- Cook: 10 minutes
- Set: 1 hour
- Makes 24 bars
Variations
- Chocolate-topped: melt 1 cup of chocolate chips with 1 teaspoon of oil and spread over the set bars.
- Peanut butter: stir 1/2 cup of creamy peanut butter into the melted marshmallows.
- UK-style chocolate rice krispie cakes: melt 7 ounces of milk chocolate with 2 tablespoons of butter and 2 tablespoons of golden syrup, stir in 4 cups of cereal and set in a lined 9×13 pan in the fridge.
- Holiday: fold in sprinkles or tint the marshmallow with food colouring.
Other Pan Sizes
- 8×8 or 9×9 pan: use half: 2 tablespoons butter, 8 ounces marshmallows, 4 cups cereal.
- 9×13 thin bars: the original ratio of 3 tablespoons butter, 10 ounces marshmallows and 6 cups cereal.
- Half sheet (13×18): double the 9×13 recipe.
Storage
Store the bars in an airtight container at room temperature for up to 3 days, with parchment between layers. Do not refrigerate them; the cold makes them hard. They can be frozen, wrapped individually, for up to 6 weeks and thawed at room temperature.
Frequently Asked Questions
- Why are my rice krispie cakes hard? The marshmallows were overheated or the mixture was pressed too firmly. Melt on low and press lightly.
- Can I use large marshmallows? Yes, by weight: 16 ounces of large marshmallows melts the same as 16 ounces of mini.
- Can I use stale marshmallows? Fresh ones melt more smoothly; stale ones can turn stringy.