In a medium-size saucepan over medium-high heat, combine butter, sugar, and
eggs. Cook, stirring constantly, until the mixture comes just to a full boil, then remove from heat, and allow to cool.
When mixture has cooled, add the graham cracker crumbs, coconut, vanilla extract, and marshmallows. Stir until the ingredients are well mixed.
Press into a 9-inch by 9-inch baking pan. Cut into small squares and serve.