Melt chocolate over a water bath, remove from heat and pour on crust spreading evenly. Set aside for 25 minutes or until chocolate begins to set.
Whisk together eggs, sugar, corn syrup, butter and vanilla in a medium bowl until smooth. Pour egg mixture over chocolate layer on crust. Arrange pecan halves on top of mixture. Bake for 30-32 minutes or until mixture is set. Cool completely before serving.