Melt chocolate and butter in a saucepan over low heat; set aside. In a mixer, beat eggs, sugar and vanilla at high speed for 10 minutes. Blend in chocolate mixture, flour and salt until just mixed. Stir in the nuts. Pour into prepared pan.
Bake for 35-40 minutes. (Don't overbake.)
Spread ice cream over the brownie until it reaches the top of the pan. Freeze. Once ready to eat, let stand for 10 minutes to thaw.
Slice and enjoy!