Gooey, crunchy Rice Krispie treats made with marshmallow and cereal are a classic, family-friendly no-bake dessert. These nostalgic squares are a beloved favorite for kids and adults.
Grease a 9x13-inch baking dish lightly with nonstick spray or butter, making sure to coat all corners to prevent sticking.
In a large pot over low heat, melt the unsalted butter, swirling occasionally to ensure even melting without browning.
Add the mini marshmallows and a pinch of salt; stir continuously on low heat until marshmallows are completely melted and smooth, ensuring the mixture does not scorch.
Remove the pot from heat and stir in vanilla extract. Immediately add the Rice Krispies cereal, folding quickly with a spatula to coat all the cereal before the mixture cools.
Transfer the mixture to the prepared pan and use a buttered spatula or wax paper to gently press it evenly into the corners without compressing too firmly. Allow to set at room temperature, at least 30 minutes, before cutting into squares.