01 -
Preheat oven to 350°F (175°C). Line a baking sheet with parchment paper.
02 -
In a medium saucepan over medium heat, melt the butter. Continue cooking past the point of foaming until it turns golden brown and develops a nutty aroma. Stir continuously to prevent burning. Once browned, transfer to a bowl and chill in refrigerator or freezer for about 10 minutes to cool.
03 -
In a medium mixing bowl, combine cooled brown butter with both brown and granulated sugars. Add the egg and vanilla, mixing on low speed until smooth, approximately 30 seconds.
04 -
Slowly incorporate salt, baking soda, and flour, being careful not to overmix the dough.
05 -
Gently fold in the rice krispies, followed by the mini marshmallows, distributing evenly throughout the dough.
06 -
Scoop dough into large balls using a 3-tablespoon cookie scoop. Place only 4-5 cookies per baking sheet, allowing ample space for spreading.
07 -
Bake cookies for 10-13 minutes until edges are light golden brown. Remove from oven, immediately sprinkle with flaked salt, and allow to cool. Cookies should have crisp edges and a chewy center.