In a large mixing bowl, use a whisk to combine the melted, cooled butter with the sweetened condensed milk, and vanilla extract until well combined.
Add the coconut, graham crumbs, chocolate chips, pecans, and toffee bits. Stir to combine until well mixed through.
Cover the bowl and refrigerate for 1 hour.
In the meantime, prepare the topping. Over low heat, melt the butter in a skillet. Add the pecans and crushed cereal. Stir well to coat until all of the ingredients are coated and slightly toasted.
Transfer topping mixture to a wide, shallow bowl to cool completely.
To assemble, roll one slightly heaping teaspoon of the cookie dough mixture into a ball. Roll into the topping mixture and place on a parchment-lined baking sheet. Continue until all cookie dough is used. Do not pile the balls.
Transfer entire baking sheet to fridge to cool and set up for 1 hour.
Pile cookies into food-safe container and keep refrigerated.