Microwave unsweetened chocolate and butter in a large microwaveable bowl on high for 2 minutes, or until butter is melted. Stir until chocolate is completely melted. Add sugar, mix well. Blend in eggs and vanilla. Add flour and mix well. Cover and refrigerate for one hour, or until dough is easy to handle.
Preheat oven to 350 degrees.Shape dough into 1 inch balls, place on lightly greased baking sheets about two inches apart. Bake 8 minutes or until just set - do not over bake. Let them rest on the baking sheet for a minute, then transfer to wire racks to cool completely.
Place frozen whipped topping and semi-sweet chocolate in a microwaveable bowl. Microwave on high 1 1/2 minutes or until chocolate is completely melted and mixture is shiny and smooth, stirring after one minute. Let stand 15 minutes to thicken. Spread over cookies, and let them stand until the glaze is set.
This recipe will make about five dozen cookies. Enjoy!