Rice Krispy Bar Recipe

Prepare pan and cereal

Line an 8x8-inch (20x20 cm) baking pan with parchment paper or lightly grease it. Measure 6 cups of Rice Krispies cereal into a large mixing bowl and set aside.

Melt butter and marshmallows

In a medium large saucepan over low heat, melt 3 tablespoons unsalted butter until just melted (about 30–45 seconds). Add 4 cups mini marshmallows and a pinch of salt. Stir continuously with a heatproof spatula or wooden spoon until marshmallows are fully melted and smooth, about 3–5 minutes. Keep the heat low to prevent scorching.

Add vanilla and optional peanut butter

Remove the saucepan from heat. Stir in 1 teaspoon vanilla extract. If using peanut butter (1 tablespoon), add it now and stir until fully incorporated and smooth.

Combine with cereal

Pour the melted marshmallow mixture over the reserved cereal. Using a buttered or lightly oiled spatula (or two lightly oiled spoons), fold the mixture to coat the cereal evenly. Work quickly — marshmallow sets as it cools.

Press into pan

Transfer the coated cereal into the prepared 8x8 pan. Use the oiled spatula or a sheet of parchment paper lightly greased to press the mixture firmly and evenly into the pan. Pressing firmly helps bars hold together; avoid compacting so tightly that bars become hard.

Cool

Allow the bars to cool and set at room temperature for at least 30 minutes. For quicker setting, refrigerate for 15–20 minutes.

Add chocolate drizzle (optional)

If using chocolate chips, place 1 cup chips in a microwave-safe bowl and microwave in 20-second intervals, stirring between intervals, until smooth (about 40–60 seconds total). Drizzle the melted chocolate evenly over the cooled bars with a spoon or piping bag. Alternatively, spread melted chocolate gently across the top for a chocolate layer.

Add sprinkles and set

Immediately sprinkle 2 tablespoons sprinkles over the melted chocolate if desired. Allow chocolate to firm at room temperature (10–20 minutes) or refrigerate for 5–10 minutes until set.

Slice and serve

Lift the bars from the pan using the parchment paper overhang. Place on a cutting board and, using a sharp knife (wipe blade clean between cuts for neat edges), slice into 12 squares. Serve at room temperature. Store leftover bars in an airtight container at room temperature for up to 3 days, or refrigerated for up to 1 week.