Step 1

Prepare brownie mix according to package directions.

Step 2

Cover prepared brownies with marshmallows immediately after baking and set in hot oven that's been turned off until they puff up about 2-3 minutes. Remove from oven.

Step 3

In a medium size saucepan bring half and half, butter and white sugar to a boil. Boil for one minute, stirring frequently not to scorch the bottom. Stir in chocolate chips, stirring mixture until they are melted and frosting is smooth. Immediately spread over brownies.