1 pkg (8 squares) unsweetened chocolate
1 cup butter
5 eggs
3 cup sugar
1 tbsp Vanilla
1 and 1/2 cup flour
Melt chocolate and butter in saucepan over very low heat, stirring constantly. Beat eggs, sugar and vanilla in large mixer bowl on high speed for 10 minutes. Blend in chocolate mixture on low speeed. Add flour, beating just to blend. Spread in greased 13x9 inch pan. Bake at 375 for 35 to 40 minutes. Cool in pan.