Step 1

Line a 9x13 pan with foil and spray with cooking spray; set aside.

Step 2

In a small bowl, heat heavy cream and white chocolate in microwave by 10 second intervals until just melted. Stir in vanilla extract until smooth; set aside.

Step 3

In a large light-colored dutch oven or stock pot over medium heat, heat butter until it starts to foam, stirring. Continue to cook until the butter is golden brown and has a nutty aroma. Turn off heat and add marshmallows. Stir until marshmallows are mostly melted.

Step 4

Immediately stir in white chocolate mixture.

Step 5

Fold in cereal and stir to coat completely.

Step 6

Gently press mixture into prepared pan. Be sure not to press down to hard to keep the treats from getting too hard.

Step 7

Top with flaky sea salt, if desired.

Step 8

Allow to cool for at least 1 hour before cutting into squares.