Grease a 9 x 13 inch pan with softened butter.

In a large non-stick saucepan, melt butter over medium heat stirring constantly until slightly golden and fragrant. There should be little brown flecks throughout the butter

Stir in the salt and sweetened condensed milk until combined

Add marshmallows and stir until completely melted. Remove from heat

Add vanilla bean and stir completely

Add cereal and stir until well coated

Add in the sweetened coconut and chopped mango and stir until well coated

Using buttered spatula or wax paper evenly press mixture into a 9 x 13 inch pan greased with butter. Sprinkle with sesame seeds if using

Cool. Cut into 2-inch squares using a knife sprayed with cooking spray or coated with softened butter.

Eat right away or wrap each square tightly with cling wrap.