1Prehea oven to 350 degrees. Grease a thirteen by nine inch baking pan.
Melt the chocolate and butter in a 2 qt. bowl in the microwave for 2 minutes. Stir until the chocolate is completely melted.
2Add the sugar, eggs, and vanilla and mix well with a spatula. Add the flour and stir to combine. Spread the batter evely into the prepared pan. Bake for 25 minutes.
3Melt the chocolate and butter for the frosting in a medium bowl in the microwave for 3 minutes.Stir until completely melted. Add the egg beaters, vanilla, and confectioners sugar until smooth. Stir in the marshmallows.
4Spread the frosting over the warm brownies. The frosting will set up as the brownies cool...When completely cooled, cut into one inch squares. Makes about forty squares.