Large Marshmallow Rice Krispie Treat Recipe: Extra Thick and Gooey Squares

This recipe transforms classic Rice Krispie treats into something extraordinary—extra thick squares with a gooey center. The secret lies in precise melting and mixing techniques.

Using more marshmallows than standard recipes creates that signature stretchy, melt-in-your-mouth texture. The larger pan size ensures generous portions while maintaining the perfect crispy-to-chewy ratio.

You’ll achieve restaurant-quality results with simple ingredients and minimal effort. The key is timing—remove from heat just as the marshmallows fully melt for optimal consistency.

Perfect for parties, bake sales, or satisfying that late-night sweet tooth. These disappear faster than you can make them.

Ingredients for Large Marshmallow Rice Krispie Treat

Extra marshmallows and thick squares make these irresistibly gooey and crispy treats.

The marshmallows are doing all the work here. Mini marshmallows melt faster and more evenly than large ones, but mixing both gives that perfect stretchy texture. I grab mine from Walmart in bulk—cheaper and you’ll go through them fast. For the butter, Land O’Lakes unsalted is my go-to, but any brand works as long as it’s unsalted. The vanilla? Don’t skip it—pure extract adds depth you won’t get from imitation.

Swapping mini for large marshmallows? Use 10 cups large instead of 16 cups mini—they’re about 1:1.5 ratio. No vanilla? A pinch of almond extract works in a pinch (but go easy, it’s strong). Out of Rice Krispies? Puffed rice cereal from the health food aisle is identical. Skip the salt if you’re using salted butter, but I always recommend unsalted for baking so you control the seasoning.

These keep well at room temp in an airtight container for up to 3 days—if they last that long. For longer storage, wrap individual squares in parchment and freeze for 2 months. They’ll soften slightly when thawed, but still taste amazing. Pro tip: press them into the pan with buttered fingers to avoid sticking.

Step-by-Step Instructions for Large Marshmallow Rice Krispie Treats

Here’s the method I use for extra thick, bakery-style treats that hold their shape perfectly.

Step 1: Prepare the Pan and Measure Ingredients

Lightly coat a 9×13-inch baking pan with the cooking spray, making sure to cover all sides and corners thoroughly. This prevents sticking and ensures easy removal of your finished treats. I like to line the pan with parchment paper as well, leaving an overhang on the sides for easy lifting.

Measure out all your ingredients before you begin. You’ll need the 10 cups Rice Krispies Cereal, 16 cups Mini Marshmallows, 4 cups Large Marshmallows, 1 cup Unsalted Butter, 2 tsp Vanilla Extract, and 0.5 tsp Sea Salt ready to go. Having everything prepped makes the process smooth and stress-free.

Step 2: Melt Butter and Toast Marshmallows

In a large, heavy-bottomed pot, melt the 1 cup Unsalted Butter over low heat. Once melted, add the 16 cups Mini Marshmallows and 4 cups Large Marshmallows. Stir constantly with a silicone spatula or wooden spoon to prevent burning.

The marshmallows will begin to soften and melt after about 5-7 minutes. You want them completely melted and smooth with no lumps. Here’s the thing—if you rush this step with high heat, the marshmallows will burn and turn bitter. Keep that heat low and steady.

Step 3: Add Flavorings and Incorporate Cereal

Once the marshmallows are fully melted, remove the pot from heat. Stir in the 2 tsp Vanilla Extract and 0.5 tsp Sea Salt. The vanilla adds depth of flavor that cuts through the sweetness, while the sea salt enhances all the other flavors beautifully.

Immediately add all 10 cups Rice Krispies Cereal to the pot. Using the same spatula, fold the cereal into the marshmallow mixture gently but thoroughly. You want every piece of cereal coated evenly. This step goes quickly—the cereal will start to soften if it sits too long in the warm mixture.

Step 4: Press into Pan and Shape

Transfer the mixture to your prepared pan. Using the spatula or buttered hands (to prevent sticking), press the mixture evenly into the pan. I find that lightly wetting my hands with water works just as well as buttering them and is less messy.

Press firmly and uniformly to create an even layer. For extra thick treats, make sure the mixture is compacted well, especially in the corners. Don’t over-press or you’ll end up with dense, hard treats rather than light and chewy ones. Let the pan sit at room temperature for 30 minutes to set completely.

Step 5: Cut and Serve

Once fully set, use the parchment paper overhang to lift the entire slab out of the pan. Place it on a cutting board and use a sharp knife to cut into squares. For clean cuts, dip the knife in hot water and wipe it between each cut.

These treats are best enjoyed the same day but will keep in an airtight container at room temperature for up to 3 days. The combination of mini and large marshmallows creates that perfect balance of gooey texture and structural integrity that makes these treats stand out from the standard version.

Creative Variations of This Recipe

Chocolate Lover’s Dream

Add ½ cup cocoa powder to the melted marshmallow mixture for a rich chocolate twist. I also fold in 1 cup semi-sweet chocolate chips with the cereal for extra melty pockets. Use Dutch-process cocoa for smoother flavor.

Peanut Butter Bliss

Stir 1 cup creamy peanut butter into the melted marshmallows until smooth. For texture, add ½ cup chopped peanuts with the cereal. I use Jif Natural as it blends in perfectly without separating.

Fruity Surprise

Mix in 1 cup dried cranberries or chopped dried apricots with the cereal for a sweet-tart contrast. The chewiness pairs beautifully with the crispy cereal. Use ocean spray craisins for consistent quality.

Salted Caramel Delight

Drizzle ¼ cup caramel sauce over the mixture before pressing into the pan. Sprinkle with 1 tsp flaky sea salt after pressing for that gourmet touch. I use Smucker’s caramel topping for ease.

Let it set for 5 minutes before the final press. ✨

Cereal Swap

Try Cocoa Pebbles for double chocolate flavor or Fruity Pebbles for a colorful, fruity variation. Both maintain the crispy texture. Use the same 10 cups measurement as the original recipe.

Marshmallow Only

For ultra-gooey treats, skip the cereal entirely and use 20 cups mini marshmallows with just ½ cup butter. Press into the pan and let set for 1 hour before cutting. These are decadent and rich. 💛

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