These brown butter rice krispie treats are soft, gooey, and packed with rich toasted flavor from browned butter and milk powder. Extra mini marshmallows keep every square chewy, while vanilla and salt balance the sweetness.
Melt 7 tablespoons (100 g) unsalted butter in a large pot over medium heat, stirring frequently until the butter turns golden brown and smells nutty, about 5 minutes.
Reduce the heat to low and stir in ⅓ cup (30 g) milk powder. Cook for 1 minute, stirring constantly until lightly toasted.
Turn off the heat and stir in ¼ teaspoon salt and 1 tablespoon vanilla extract until fully combined.
Add 10 oz (300 g) mini marshmallows and return the pot to low heat. Stir constantly until the marshmallows are completely melted and smooth.
Turn off the heat and fold in the remaining 4 oz (100 g) mini marshmallows just a few times to create extra gooey pockets throughout the treats.
Add 7 cups (200 g) Rice Krispies cereal and gently stir until evenly coated with the marshmallow mixture.
Transfer the mixture to a parchment-lined 8x8-inch (20x20 cm) baking pan. Gently press it into an even layer using a spatula without compacting it too firmly.
Let the brown butter rice krispie treats cool completely at room temperature for about 1 hour before slicing into squares.
Notes
Brown the Butter Carefully: I like to stir the butter constantly once it starts foaming so it develops a deep toasted flavor without burning. Don’t Overmix the Marshmallows: Folding in the last batch of mini marshmallows at the end keeps the treats softer and gives them pockets of gooey texture. Press the Mixture Gently: I always lightly press the cereal mixture into the pan because packing it down too firmly can make the treats dense instead of chewy.