1. Add the butter to a saucepan over medium heat and cook until it turns golden brown and smells nutty. Remove from the heat and let it cool for 10 minutes.

2. In a large mixing bowl, whisk together the browned butter, brown sugar, and granulated sugar until smooth.

3. Add the eggs and vanilla extract, then mix until fully combined.

4. In a separate bowl, stir together the flour, baking soda, and salt.

5. Gradually mix the dry ingredients into the wet ingredients until a soft dough forms.

6. Fold in the crispy rice cereal gently so it stays light and crisp.

7. Scoop the dough into balls and place them on a parchment-lined baking sheet. Press mini marshmallows on top and around the sides of each dough ball.

8. Bake at 350°F for 10 to 12 minutes, until the edges are golden and the centers are just set.

9. Let the cookies cool on the baking sheet for 5 minutes before transferring to a wire rack.