Best Basic Fudge Brownies

4 bars (4 oz.) unsweetened baking chocolate, broken into pieces
3/4 cup butter
2 cups sugar
3 eggs
1-1/2 tsp. vanilla
1 cup flour
1 cup chopped nuts (optional)

Preheat oven to 350* Grease a 9 by 13 inch baking pan. Microwave
chocolate and butter for 1-1/2 minutes until melted, and mixture is smooth when stirred. Add the sugar and stir until well blended. Add the eggs and vanilla; mix well. Add the flour and nuts; stir until well blended.
Spread into the prepared pan. Bake for 30-35 minutes or until a wooden pick inserted in the center comes out clean.