Rice Crispy Marshmallow Recipe Really Good Rice Crispy Treats Recipe?

Really good Rice Crispy Treats recipe? - rice crispy marshmallow recipe

Today I had the best crispy rice is Starbucks. You can see pieces of marshmallows in it. If you bite, crispy puffed rice, but there is a sweetness of marshmallows, a perfect combination.

How can I crispy rice is it? I did this for years, but I remember getting a little difficult.

Thank you for your help!