beat the eggs and salt together in a large mixing bowl until frothy. Add the sugar and beat until the eggs are thick and pale yellow, about 2 to 3 minutes. Add the vanilla extract and beat an additional 30 seconds.
Put the margarine and chocolate in a microwave safe container and microwave on high for 1 minute. Stir to insure that the chocolate has melted. Microwave an additional 30 seconds, if needed.
With the mixer running, pour the melted chocolate into the egg mixture. Add the flour and beat 1 minute. Scrape down the sides of the bowl and beat an additional 30 seconds.
Spray the cake pan with a pan release spray and pour in the brownie batter. Place the pan on the top rack of the oven and bake 15 to 20 minutes until the center is barely set.
Remove the pan from the oven and let cool. Top with the ganache and place in the freezer for at least 1 hour.
To serve, remove from freezer and slice immediately. Allow to come to room temperature before serving.
1/2 cup (4 ounces) semisweet chocolate chips
1/4 cup heavy cream
Put the chocolate chips and cream into a microwave safe bowl. Microwave on high for 1 minute. Remove the bowl and stir with a whisk or fork until well mixed. Use immediately. If using the ganache later it will need to be reheated.